Part of Me
by turambar499
Summary: "You know, backup'll be arriving soon if you want to save some for the rest of the League…" Felicity began. "Nah, I think I've got it," Kara replied conversationally into her communicator, glancing idly at her chest as a grenade bounced off it.
1. Chapter 1

_This story takes place on an Earth where Supergirl is a part of the rest of the Arrowverse. Major events referred to in the story that have been shown on Supergirl, The Flash, or Arrow are assumed to have happened in some general shape or form on this Earth, but the main players and chronological order won't necessarily be the same, and some interpersonal relationships are also different. Legends of Tomorrow's canon won't be too relevant, but it's assumed the crew is on present-day Earth for the duration of the story. The rating for this is K+ for occasional mild language and suggestive scenes._

 _As always, all characters belong to DC Comics and the CW. This is written purely for fun. Thanks so much for reading. I appreciate it._

…

"Nope," Alex laughed, as Kara groaned again. She let go of her sister's arm and put her hands on her hips in frustration.

Despite revealing herself as Supergirl years ago and getting pushed to her limits in training by the DEO, and later the Justice League, Kara still came out on the losing end in the Kryptonite training room against Alex. Admittedly, Kara was a fast learner, and in the early days of her training, particularly on days when Kara's focus was razor-sharp, she seemed to hold her own or even beat Alex one-on-one. However, she eventually caught on that it was Alex who typically held back, despite her constant lectures to Kara about forgetting the fact they were family.

"You have to really jut your hips back, or you won't get the right leverage," Alex explained, the sisters lining up to try again. Kara was trying to counter Alex's punch with a throw, but she couldn't arrange her body the right way to execute it correctly. Squaring off, the sisters closed the distance between them again and resumed trading blows, their sequence of punches and counters flowing from one motion to the next.

It'd taken Kara learning enough to actually become a decent fighter to realize that, when Alex brought her A-game, when she viewed Kara as an _adversary_ and not her little sister, Alex was in fact way, way above her level. She'd become sick of how wide the gap still was between them, so she'd recently bugged Alex to step up their sessions and help her learn all the tricks and techniques that Alex used effortlessly.

Finally, within the flow of their sparring session, Alex threw a long, telegraphed punch at Kara's face, and Kara spun around, blocking the punch first before grabbing her sister's arm and twisting her body so that her back was to Alex. She tried to use that grip to flip Alex over her shoulder, but she couldn't get her sister all the way over, leaving Alex draped over her back like a sack of potatoes.

"Nope," Alex laughed again. "You need to flip me, not give me a piggy-back ride."

"I'm trying!" Kara said, letting go of Alex so she could get back on her feet. "You make it look so easy."

"Hey, we've only just started practicing this throw," Alex soothed. "You'll get it eventually."

"I know," Kara sighed. "I just get embarrassed watching Oliver, Roy, and Thea training together, with all the crazy martial arts stuff that they do. All the sticks, and the flying kicks, and the counter moves. I'm standing to the side, like, 'Um, I can punch really hard…'"

"Hey, that's not fair. You can hold your own in a fight. The DEO wouldn't have let you out of our sights if you couldn't," Alex reasoned.

"Yeah, I know," Kara agreed again. "I guess I'd just like it known by any bad guys out there that my skills go beyond flying and zapping things with my eyes."

"Speaking of which," Alex said, glancing up at the ceiling as an alarm started to go off. "Sounds like a bad guy needs dealing with."

Kara tilted her head, listening to the specific rhythm and cadence of the alarm. "That's not a DEO alert. That's Justice League."

"Better get going, then," Alex prodded, pushing Kara along towards the door.

"Alright, alright," Kara said, waving her arms as she jogged along. "But we are definitely picking this up again later," she finished, before using her superspeed to rush out of the compound.

…

 _Seriously. Why the punching?_

Kara had to admit her cousin had a point as she effortlessly mangled guns and socked gang members into unconsciousness. She could still remember those days in National City when she and Clark romped through downtown, taking down robbers and car thieves and every other manner of petty criminal, but even now, despite both of them having nicknames that included the words "of Steel," bad guys still insisted on trying to punch their way past the Kryptonians. Inevitably, the effort ended poorly for them.

Once Kara had flown out of the DEO, Overwatch linked up with her official JL communicator earpiece and briefed her on the situation. A crime syndicate in Keystone City had gotten a bit too big for its britches and was attempting a brutal takeover of an impoverished section of town using an impressive array of military-grade weapons they had acquired illegally. Strictly speaking, Kara wasn't the closest JL member available, but the magnitude of the event required what Felicity coined "a Super touch."

"You know, backup'll be arriving soon if you want to save some for the rest of the League…" Felicity began.

"Nah, I think I've got it," Kara replied conversationally into her communicator, glancing idly at her chest as a grenade bounced off it. She caught the grenade before it hit the ground and cradled it tightly against her stomach, covering it up with both arms. An entirely underwhelming explosion followed a few seconds later, and she opened her arms to let the grenade fragments fall harmlessly to the ground. She then sped over to the gangster who had hurled it at her and knocked him unconscious, the man too flabbergasted by her powers to even try defending himself.

"Show off," a voice teased behind her.

Kara glanced back to see the familiar lightning-streaked red suit of the Flash leaning against a wall, arms crossed as he surveyed her handiwork. "You're just lazy," she retorted.

"How am I lazy? I just got here!"

"Exactly! How can you be the fastest man alive and still be late?"

"Hey, disaster relief supplies aren't going to deliver themselves."

"Excuses, excuses."

Barry laughed and walked over to her. "Fine. You're amazing, and I'm a slacker. Happy?"

Kara returned his laugh with a playful smile. "I don't know," she replied airily, tilting her head up as he stood in front of her. "I'm still annoyed at you."

Barry grinned as he leaned forward, cupping her face with both hands like she was the most precious thing in the world. "Really? Still?" he chuckled.

"Yup. You could say I'm 'super' annoyed," she teased, placing her hands softly on his upper arms.

Barry huffed in amusement at her corny joke. "Unbelievable," he muttered, the smile never leaving his face as Kara felt the gentle pull that brought her lips to his. They stayed in that embrace for a few seconds, happy to be with each other for the first time in weeks. When they finally pulled away, Barry told her, "I've missed you."

"I've missed you, too," she replied.

Barry's smile grew wider, but his eyes also carried a mischievous glint that she knew all too well. Before she had a chance to process this, he quipped, "By the way…," before disappearing in a blaze of light and wind. Kara briefly registered a distant _smack_ followed by someone groaning, and then Barry was suddenly back in front of her.

"…you missed one," he finished cheekily.

Rolling her eyes and shaking her head, Kara wrapped her arms around Barry's neck to bring him close to her again.

"You know I can see you two, right?" Felicity chimed over the comms.

…

"Barry, don't you think Kara would prefer you two spend time alone in your own place?" Joe asked exasperatedly, over the sound of button mashing, as he walked through the door of his house.

"Actually, I'm having a great time kicking Barry's butt," Kara laughed, dropping her controller in satisfaction.

"What? You finished last!" Barry replied incredulously.

"Yeah, but I knocked you down to fourth," she shot back.

"Only because you threw a freaking blue shell at me."

"Hey, if I'm not getting first, neither are you." Barry responded with a glare, so she stuck her tongue out at him petulantly.

"You haven't seen each other in weeks, and you want to play video games?" Joe pressed on skeptically, hanging up his coat and putting away his shoes after having just finished his day at the police station.

"I don't have a TV at my place," Barry pointed out.

"You live in a huge loft. How can you not afford a TV?"

"Hey, that loft cleaned me out. Captain Singh hasn't given me a raise in years."

Joe turned his head to Kara, but she put her hands up defensively. "Don't look at me. I get a low-level reporter's salary."

Rolling his eyes, Joe shook his head, muttered "kids this days," and plopped heavily into his favorite armchair next to the couch. "What a day," he continued, emphasizing each word tiredly. "That gang's attempted coup was huge. No wonder Keystone called us for help in processing all the perps."

"At least Kara secured all the weaponry so you didn't have to put any officers in danger," Barry pointed out.

"Yeah, that's true," Joe conceded. "Still, I am too tired to make dinner. You kids want anything? I'm going to order out."

"Oh, no need," Kara replied brightly. "We took care of it. Dinner's almost ready," she finished, tilting her head towards the kitchen.

Bewildered, Joe glanced at his watch. "I literally saw you two barely an hour ago. How did you–"

"Superspeed."

"Heat vision."

A moment passed. Then Joe simply shook his head, got up, and headed to the kitchen. "I'll never get used to this stuff," he sighed. Kara glanced over at Barry, and he in turn glanced back at her. Without saying a word, they both dissolved into laughter at Joe's befuddlement.

…

Blearily, Kara cracked open one eye as her hearing caught the telltale chirp of two JL alerts coming from the nightstand.

She knew what they were for: a reminder that a major conference would be taking place in a couple hours and that every member needed to be near a primary League hub so that he or she could participate. S.T.A.R. Labs was one such hub, so it was no problem for her to simply remain in Central City after handling the gang business in neighboring Keystone. True, she could have gone back home, where the DEO was another hub, but as she felt the rhythmic breathing underneath her head, she was glad she'd stayed.

After catching up the night before with Joe and later Iris and Wally, who joined them for dinner, Kara and Barry had gone back to Barry's loft together. After having been separated for too long, he on a humanitarian mission and she on a DEO-organized war games practice scenario, alone time was a must. Now, the following morning, Kara was content to simply lie in bed, her head on Barry's chest as she felt his solidness against hers.

Life had gotten so busy since the two of them, along with Clark, Oliver, and a few others headed up the formation of the Justice League. Becoming an actual organization meant they were no longer accountable only to themselves and that they couldn't just be vigilantes or good Samaritans anymore. The responsibilities weighed heavily upon them all, but for Kara and Barry, they positively wrecked havoc upon their life as a couple. They spent huge chunks of time apart, they always had to keep their larger obligations in mind whenever they worked together, and opportunities to actually build a life with one another were few and far between. Advanced technology or not, superpowers or not, they weren't robots, and anyone would acknowledge there were limits to what they could or would do to make things work.

In spite of that, Kara could feel deep down that she was happy with how things were going, and she could tell Barry felt the same. Leading dual lives was practically a habit to the both of them, and in a way, as hard as the periods of separation, distance, and responsibility could be sometimes, it led them both to cherish their time together all the more. They each understood on a fundamental level how important being a hero was to the other, an insight only a select few could ever truly comprehend, and a reason they connected so well.

Besides, if they were ever desperate for a break to just be together for a bit, they could literally speed towards each other, she flying and he running, no matter where they were.

 _Ah, the perks of being "super."_ Kara smiled to herself at the thought of her and Barry sprinting at each other from opposite sides of the world, pressing her cheek softly into his chest. He began to wake up under her light pressure, and his hand sleepily drifted over to stroke the rat's nest that was her bedhead.

"Morning."

"Morning," she mumbled back, too comfy and enjoying too much the sensation of his hand through her hair to move.

"Last night was fun."

"It was. Plus, no furniture was broken this time."

A groan. "Kara, that happened _once_."

"Yes, and I will never let you forget it," she giggled.

Barry laughed in defeat. After a pause, he asked, with a cheeky tone of voice, "Want to go again?"

She chuckled. _Typical_. "You conveniently slept through the JL notifications we both got on our comms. We're due in S.T.A.R. Labs in, like, an hour and a half," Kara said.

"You realize even if we took the scenic route, we could both be there in about thirty seconds," Barry countered.

"You know how long this meeting could go," she replied, finally shifting her head to face him directly. "Do you _want_ to face J'onn and Oliver on an empty stomach?"

"Point taken," he conceded. After a pause, he asked her, "So which one you taking this time? Food or coffee?"

Considering for a moment, Kara finally said, "Food."

"Alright, I've got coffee," Barry agreed. "Meet you back here."

In a blink, both jumped into superspeed, pacing through their individual morning routines before vanishing from the loft to grab the first meal of the day.

…

"Security's not so bad."

"Malcolm Merlyn infiltrated your Bunker, Oliver. Repeatedly."

"You should talk. Exactly how many evil speedsters have gotten into S.T.A.R. Labs?"

"Didn't the Music Meister infiltrate the DEO and then leave via interdimensional breach?"

"Okay, okay," Clark interrupted, raising his voice slightly to calm the squabbling that was starting to develop. "We can all agree that, if we're going to use our bases as Justice League hubs, we should probably make an effort to secure them."

Kara tried not to get dizzy at the array of extra screens that had been brought into S.T.A.R. Labs to accommodate all the different locations from where Leaguers were transmitting. One screen showed a crowd of people, with Oliver in the forefront and the grim, underground environment of the Bunker in Star City making up the background. In another, she saw J'onn and Alex checking in from the DEO base in National City. Kendra and Carter from St. Roch. Wally from Blue Valley. Mari from Detroit. Roy from Hub City. And so many more, from many different locations and, indeed, different dimensions. The planning alone to get everyone in on call was a feat in and of itself.

And then, of course, there was her cousin in Metropolis, coordinating it all.

"We'll start with S.T.A.R. Labs, since it's the most centrally located of our bases," Clark continued.

"Guess Central City lives up to its name," Barry quipped, sitting in a chair across the room from Kara.

"We'll probably need some help," Caitlin pointed out, sitting in the center of the semi-circle console in the middle of the room. Since the formation of the League, Caitlin had taken a leading role as the primary S.T.A.R. Labs point of contact. "Cisco's got a lot going on already, patrolling the multiverse with Gypsy."

"Yeah, I'm stretched a bit thin," Cisco agreed from his own screen.

"I can come help," Felicity chimed in, her blond head popping up behind the heavily-muscled, leather-clad figures of Team Arrow.

"Having a military perspective might help as well in tightening up security," J'onn said. "Alex will join you." Beside him on the screen, Alex nodded her head.

"Should I head back to National City, J'onn?" Kara asked.

"I think we'll be better off with you staying in Central City for now," Cisco interjected. "Implementing the security upgrades we've drawn up could require heavy lifting. Like, _literal_ heavy lifting," he clarified. Kara nodded her agreement, shooting a small smile in Barry's direction, which he immediately returned. Neither would begrudge the additional time together.

"Sounds good," Caitlin agreed. "I'm going to get Harry from Earth-2 here as well to consult on how we handle the particle accelerator with these new upgrades. The only one who knows that thing better than Harrison Wells is…well, Harry Wells."

"Okay," Clark said. "We'll use S.T.A.R. Labs as our test example and apply the lessons learned to secure our other bases. Keep us informed."

"Will do," Caitlin confirmed.

"Right. That concludes our meeting. Thank you all for conferencing in. We'll be in touch soon." With that, Clark cut his video feed, and one by one, the rest of the screens went dark as well.

"Well, guess we've got a lot of work to do," Barry said.

…

Over the next week, S.T.A.R. Labs went through a badly needed major security overhaul. The amount of work required would normally take a fully human crew months to complete, but the technical team of Caitlin, Felicity, Alex, and Harry found having the Girl of Steel and Scarlet Speedster around quite handy.

"Yeah, yeah, just hold that steady," Alex muttered to Kara on the roof of the lab, a screwdriver held between her teeth as she fiddled with wires on a large surveillance turret that Kara was holding in place with one hand.

"Right, we'll need cables run along here, here, and here," Harry pointed out, back hunched over a schematic of the room they were updating. A rush of air blew around the room, and when Harry straightened up, Barry was standing behind him, all the cables in the room already in place and a politely inquisitive look on his face, waiting for his next task.

"I cannot _believe_ you've all set up literally _nothing_ ," Felicity said for the fifth time as she and Caitlin sat side by side at the semicircle console in the main lab, updating defensive protocols to be applied across the lab.

"We get it Felicity," Caitlin intoned.

"No security."

"We know."

"No alarms."

"We know."

" _Nothing at all_ stopping someone from walking through your front door."

"Infiltrated by three evil speedsters. We already covered this, Felicity."

"I mean, sure, Merlyn's gotten into the Bunker, but he's League of Assassins. At least we have a secret elevator entrance! We're underground! No one else knows we're there. This place," she said, building up steam as she actually stopped coding to throw her arms up, indicating the entirety of S.T.A.R. Labs, "is out in the open! It's _been_ out in the open for forever! _I_ could infiltrate this place."

Caitlin sighed. "Felicity, are you here to help or are you here to be outraged?"

Felicity paused, glancing at her hands, which were still thrown up in the air. She lowered them slowly, a bit embarrassed. "Sorry," she said, clearing her throat. "I'll stop." She resumed her coding.

Caitlin laughed, sure that was not the first time someone had brought Felicity's own theatricality to her attention. "It's nice having you here to lend a hand," she soothed. Felicity thanked her with a smile, a smile that quickly disappeared as she jumped from a loud noise suddenly sounding off.

"I stand corrected," Felicity said, checked her console. "You _do_ have alarms."

"Unfortunately, that usually only means one thing," Caitlin replied ruefully. She pressed a button on her own side of the console to tap into the audio system for the lab. "Everyone get down here. There's trouble in the city." Within moments, Kara, Barry, Alex, and Harry were at her side.

"What've you got?" Barry asked her. In response, Caitlin brought up live camera footage of downtown Central City, allowing them to witness scenes that were chaotic and, frankly, bizarre.

Seemingly everyone had emptied out of their cars and all the nearby buildings. Half of the people were punching the living daylights out of each other, yanking each other's hair, and generally pummeling anyone they could reach with shopping bags, cell phones, umbrellas, and keys. The rage and aggression in their faces were almost feral in nature. The other half was cowering on the ground, under idling cars, or against the walls of buildings, making no effort to escape even when the brawlers seemed to be blatantly ignoring them. It was as if they were paralyzed with terror as they lay prone on the ground, curled in the fetal position, or rocked back and forth, a reaction among too many people that simply didn't match the situation the S.T.A.R. Labs team was witnessing.

"What the…?" Harry couldn't finish his question, expressing the confusion on all of their faces.

"I've got a really bad feeling about this," Caitlin muttered.

"Felicity, can you get eyes on anyone suspicious? Anyone who might have caused this?" Kara asked.

A flurry of typing. "No," Felicity admitted, shaking her head. "There's just too much mayhem. It's impossible to know where to look or what to look for."

Now all business, Barry pulled his cowl over his face, adjusting the eyepieces so that it fit snugly. "We'll have to figure it out then. Stay alert on comms. Supergirl, I could use a hand."

"Whatever you need, Flash." A blink, and both superheroes had zoomed out of the lab.

…

"What…is going on?"

Kara and Barry stood flabbergasted at the edge of the scene in front of them, momentarily unable to process the absolute chaos. Some people indiscriminately beating each other into oblivion. Other people screaming their heads off, folded into a ball, or clutching desperately to a wall or the ground as if the world would disappear at any moment. There wasn't any single thing to which the people were reacting. It was simply anarchy.

"Would they…would they stop if we separated everyone?" Barry asked dubiously, indicating the brawlers. His answer came when one particularly nasty fight in front of them between two women got broken up as a man from a different fight was bodily tossed between them, forcing them apart. Instead of reengaging, the two women turned and started picking fights with new partners.

"I'm guessing 'no,'" Kara quipped, unnerved.

After a couple more seconds of observation, Barry said, "We might have to just knock everyone out and hope they come to their senses when they wake up."

"With what? Some sort of sleeping gas?"

"I was thinking a more direct approach. We're both fast enough that we might actually get through this crowd."

Kara sighed, catching Barry's drift. "I really hate the idea of having to whack all these people in the head."

A shrill scream turned both of their heads, and they caught a woman chasing a man down the sidewalk while swinging an antique lamp on a chain like a flail and screaming bloody murder.

"On the other hand…" Without finishing the thought, Kara and Barry burst into action. Kara sped up to the woman, caught the lamp in one hand, and lightly smacked the woman in the forehead with an open palm. The woman crumpled to the ground unconscious at Kara's slight application of superstrength. "Sorry," Kara muttered, wincing slightly. Turning around, she saw Barry similarly handle the man, who also collapsed to the ground.

"We might as well split up," Barry huffed, dragging the man's body to prop up against the side of a building, relatively out of harm's way. "You take care of this side of the city. I'll go to the north side."

"Got it. We'll meet up after everyone's down and try to figure something out."

"Copy that. See you soon." Kara's hair flipped momentarily in her face as Barry zoomed off. As she turned to deal with the riot in front of her, her hair flipped in the opposite direction as Barry reappeared in front of her.

"Almost forgot," he said, smiling, before giving her a quick peck on the lips. Then he rushed off again.

 _Dork_ , she thought to herself, a smile refusing to leave her face as she smacked humans into dreamland.

…

Soon, using her superstrength and superspeed, Kara had arranged rows of unconscious people on the street, bruises blooming on their foreheads and either a headache or mild concussion in their immediate futures. She felt bad inflicting these injuries on the mass of people, but as she had already had to stop one man from gouging out a woman's eyes with his keys, another from kneecapping another man with a lug wrench, and a woman from strangling her opponent with a belt, she figured this was the lesser of two evils.

The brawlers on her side of the city taken care of, Kara turned her attention to the rest of the people seemingly paralyzed, unwilling or unable to move. She moved from person to person, trying to encourage, reassure, cajole, and otherwise convince them that there was nothing threatening them, but to no avail.

"You don't have to be afraid," she tried again, moving to a man hugging his legs, his face buried in his knees. "There's no danger anymore," she said, placing a hand gently on his shoulder. She heard some loud, almost exaggerated sniffing, and then the man lifted his eyes, locking her in his gaze.

"Are you sure about that?" he asked, in a taunting voice. His eyes glowed red.

Kara tried to look away, but she lost herself in the man's gaze. Unblinking, she felt an indescribable, violent fury overcome her senses. Her body experienced a massive jolt, like every one of her muscles had been shot through with adrenaline, her primal instincts going into flight-or-fight mode, except that "flight" was the further thing from her mind.

She blinked. The man was gone, but she saw all these people cowering on the ground. These whining, sniveling weaklings, so incapable of fending for themselves that they crouched in fear. Didn't they know who she was? Did they think she had time to hold their hands and give them hugs? She was _Supergirl_ , she was more important than all of them combined, and they should be _punished_ for wasting her time like this.

Standing up, fists clenched, Kara stalked to the nearest human, curled up in a heap and not even registering the honor he should feel at having his existence snuffed out by a goddess. It was time for the humans to learn respect. Cocking back her fist, Kara prepared to turn him into a greasy stain in the pavement.

 _No!_

Kara's fist stopped halfway to its target, and her eyes widened. "What's…what's happening?" she stammered to herself. Stumbling, Kara backpedaled away from the oblivious civilian she was just about to actually _murder_ , shaking her head furiously. Her body trembled, still shot up with this ferocious anger that she couldn't explain, her pulse racing, but she forced herself to her knees, hands grinding up the pavement beneath her until her fists were filled with gravel. Her eyes burned, as though she could literally feel them glowing red in a sinister way that had nothing to do with heat vision.

Desperate, she raising a shaking hand to the JL communicator in her ear. "Flash? I…I need help."

Static.

"Flash? Overwatch? Is anyone there?" she repeated urgently. Still, all she heard was static.

"Aww, is the Girl of Steel all alone?"

Still on all fours, Kara turned her head to the sound of the voice, and her stomach churned at the sight of the leather-clad blonde stalking towards her. "Psi," she muttered.

"The one and only," Psi taunted. "I thought you can leap tall buildings in a single bound. To me, it looks like you've fallen and you can't get up."

Too much. Everything was too confusing to process, and Kara felt her desperate grip on herself slipping. The red burning sensation shot through her eyes again, and she got to her feet. "You picked the wrong time to test me," she growled.

Psi laughed lightly in response, which enraged Kara even more. "Actually, I'd say this is the exact right time."

Unable to hold back any longer, Kara's body left the ground, aiming to flatten the bothersome meta, but in that instant a pulse shot from Psi's forehead and sent her crashing back down to her hands and knees. Immediately, she felt another jolt through her body, but now her instincts swung painfully and drastically in reverse, now squarely in "flight" mode rather than "fight." Her vision clouded, her heart was threatening to burst out of her chest, and she felt as if pillows were clamping over her ears. Her brain, so full of aggression and rage just moments before, now screamed at her to get up and run, but at the same time her limbs felt glued to the concrete underneath her. She got the vague sense of laughter somewhere above her. Psi, maybe? Kara didn't react. She couldn't.

In her mind's eye, people were shouting, running away in fear. She tasted the acrid smoke of burning cars, listened to the chaos of panicked steps crunching broken glass underfoot.

 _"Look at that city. They worship me. And those who don't, will."_

Cat Grant's screams echoed through the night air as she plummeted, seemingly to certain death from the rooftop of CatCo.

 _"True power, Cat, is deciding who will live and who will die."_

She saw Alex thrown bodily through the air, her trajectory only stopped by the unyielding surface of a car door, and heard through her superhearing the unmistakable crack of a bone breaking.

 _"Deep down, you hate me."_

Her potential for anarchy, for absolute power, for ruthlessness. For _evil_. What if no one could stop her? What if she couldn't stop _herself_? The panic swirled faster and faster inside her mind, completely paralyzing her limbs in terror. A disconnected part of her brain, though, registered that something else required her attention, and she raised her head, only to see a blurry figure through her tunneling vision.

"Well, it's been fun," Kara vaguely heard. A sudden wave of weakness and nausea overcame her, and a flash of green exploded in front of her eyes. A stab of pain, then darkness.

…

 _Author's notes: In my head, this story is a spiritual sequel to my other story, "World's Newest," but I won't be referring to anything here that's specific to World's Newest. I consider that one more as the history and context for Kara and Barry's relationship and the Justice League's formation, but it's completely unnecessary to follow this story._

 _Felicity's complaints about the S.T.A.R. Labs security are taken from The Flash 4x05, "Girls Night Out."_

 _Some of Kara's thoughts are direct dialogue from Supergirl 1x16, "Falling," and Supergirl 2x02, "The Last Children of Krypton."_


	2. Chapter 2

Alex slammed her hand into the desk as she watched Kara's body slump limply to the ground on her screen in S.T.A.R. Labs. "Kara! _Kara!_ " she yelled frantically into the microphone in front of her.

Felicity shook her head in frustration, typing furiously. "I don't understand," she growled, grinding out every syllable. "City cameras are still working, but our communication's been knocked out. It's like some sort of dead zone just descended on the area. And where the _hell_ is Barry?"

"Who's that woman?" Caitlin asked, unnerved at the sight of the Girl of Steel getting knocked out with a single punch.

"Her codename is Psi," Alex replied brusquely, trying to get what she felt like were obvious details out of the way. "She's got psychic abilities."

"And apparently a superpowerful punch."

"I don't think so," Harry jumped in, playing back the feed right before Kara was knocked out. They watched Psi remove a bulky glove from her hand before walking up to her victim, and Harry magnified the image of Psi's exposed fist. "Are those some sort of…brass knuckles?"

"No," Caitlin replied in shock, pointing to a reading on the screen next to the image. "Those are _Kryptonite_ knuckles. She must have been hiding them under a lead-infused glove."

"We can figure out why she has those later. How do we help Kara if we can't reach her or Barry?"

"I've got backup inbound," Felicity quickly replied, aware of Alex's growing panic for her sister. "Wally and Kendra will get there first. I'm sending him Kara's location before he hits the dead zone."

"And Kendra?"

"She'll patrol the area to see if she can find Barry. Something must have happened for him to be missing this long. Wally can get Kara out of there much faster."

"But will he get there before Psi does anything else to her?" Alex insisted.

"I think that won't be a problem anymore," Harry said. When Alex turned to him, he pointed to her screen, still playing live camera footage, and she saw Psi had disappeared into the crowd, which seemed to be slowly coming to its senses. Those paralyzed with fear were starting to amble about aimlessly, shaken but otherwise healthy. Those deadlocked in vicious brawls and subsequently knocked out by Kara were starting to awaken, rubbing their foreheads in pain but no longer attempting to tear out each other's throats.

"What—where did she go?" Alex demanded. A quick scroll through the various feeds Felicity tapped yielded no sign of the villainous meta. Moments later, a blaze of lightning briefly lit the screen as a new figure appeared at Kara's still form. Alex's heart ached slightly for Kara at seeing, not the familiar dark red form of Barry picking her up, but rather the yellow suit of Kid Flash, but she was grateful all the same when Wally cradled her sister and raced off screen.

"Good, Wally will be here soon," Felicity said.

"In the meantime, we need to figure out what's going on," Caitlin continued. She brought up a new still image from the day's camera footage, a picture showing the man Kara had approached before everything turned sideways. "That man that Kara tried to help—that was Rainbow Raider."

"Rainbow…who?" Alex asked, bewildered.

"Roy G. Bivalow. Codename: Rainbow Raider," Caitlin explained.

"Actually, Cisco said his codename was Prism…" Felicity began, before trailing off at Caitlin's annoyed look.

"Can't I get just one name? I'm not that bad at them!" Caitlin huffed.

"Well…" Felicity started uncertainly, then thought better of it and shut her mouth.

"Yes, Dr. Snow. You _are_ bad at them," Harry interjected, finishing Felicity's unspoken thought. Caitlin shot him a dirty glare.

"Okay, whatever," Alex interjected, annoyed that they had gotten off topic. "So, Rainbow Raider," she began, "he's another metahuman, I assume?"

"Yep. His powers allow him to incite rage into anyone he makes eye contact with. That explains all the fights in the streets."

Alex nodded. "Psi's powers can incite fear. That explains the other half of the crowd."

Just then, a smear of yellow appeared in the main lab as papers blew everywhere, and there was Wally, holding Kara in his arms.

"Kara!" Alex immediately said, rushing to her side.

"I think she's okay," Wally said, uncertain but cautiously reassuring. "She's definitely breathing."

"Get her in the med bay," Caitlin commanded, walking to a cabinet as she did so. As Alex helped Wally carry Kara onto the medical bed in one of the infirmaries connected to the main lab, she double checked Wally's assertion and confirmed that Kara was indeed breathing normally. "Okay," Caitlin continued, coming back with a handful of supplies that she dumped onto a nearby tray table while checking with a sweep of her eyes that Kara was properly situated on the bed. "The rest of you, out."

"Are you sure there's nothing else we can do?" Wally asked.

"You all need to figure out what's happening," Caitlin replied as she checked the vital signs of her patient and attached electrodes to various areas of her body. "Supergirl and Flash are powerhouses in the League. We need to know what's going on, or the rest of us are going to be in a lot of trouble."

"Copy that," Felicity replied. Without a word, she, Harry and Wally dispersed to other areas of the lab, leaving Caitlin to do what she did best.

"I'm not going anywhere," Alex said stubbornly. A part of her wanted to shove Caitlin out of the way and take charge of Kara's treatment herself, but this was S.T.A.R. Labs, not the DEO, so she didn't have in-depth knowledge of her resources. Plus, while her own scientific résumé was impressive, as a doctor Caitlin was unparalleled in the League, and Kara couldn't be in better hands.

"Never thought you would," Caitlin returned, a wry smile on her face. "Besides, I need your help." Reaching to the tray table, she picked up what looked like a strange pair of binoculars. "Use your fingers to hold Kara's eyelids open."

"What? Why?" Alex asked, confused.

"We have to make sure she's not whammied anymore."

Unsure of what that meant, Alex nevertheless obliged and gently pulled open Kara's eyelids. Caitlin held the binoculars over Kara's eyes and flipped a switch, and suddenly a pulsating pattern of different colored lights flashed onto her sister's face. For a moment, Alex didn't see anything happen, but then suddenly Kara's eyes glowed an angry red, so brightly that Alex nearly lost her grip on her eyelids in surprise. As Caitlin continued to hold the flashing lights over Kara, however, the red subsided back to Kara's familiar, cool blue irises.

Sighing in relief, Caitlin turned off the binoculars. "Okay, you can let go now." Alex did so.

"What just happened?" she asked.

"In normal humans, the rage Rainbow Raider incites wears off, but for some people, like Barry and Kara, their physiologies allow them to resist his power, if only for a while. But, as their bodies try to fight, the rage just builds and builds until—"

"—they explode?" Alex finished.

Caitlin nodded. "Barry's been whammied before, and the last setup we used to cure him was big enough to fill a van. We've miniaturized it since, in case it ever happened again." She put down the binoculars and switched back to traditional doctor mode, continuing her checkup of the Kryptonian. "Kara's response was different from Barry's. Barry steadily got more and more angry, but Kara seemed aware enough to know something was wrong. Kryptonian biology, I guess."

"Yeah well, he was still able to freeze her long enough to get away," Alex pointed out glumly, remembering how tightly she'd clenched her hands as she'd watched Kara's encounter with the meta on her screen back in the lab.

"Don't worry, I'm sure Felicity and the rest will track him down soon," Caitlin reassured her, using a small flashlight to do one final scan of Kara's pupils. Sighing, Caitlin put down the light, saying, "As far as I can tell, she's okay. She's not showing any lasting damage from that Kryptonite punch, but I'm less familiar with Psi's powers. Do you know if they have any long-term effects?"

"Not usually," Alex replied, "but we've never had a case of someone getting hit by _two_ mind-altering meta attacks."

"I see," Caitlin said. Sighing again, she continued, "Unfortunately, there's nothing else I can check on for now. Without doing anything more invasive, I won't know more until she—"

Which is as far as she got, for at that moment Kara sucked in a huge breath and her eyes snapped open. They were glowing.

With no time to even cry out a warning, Alex and Caitlin both dove backwards as blazing energy streamed out of the Girl of Steel's eyes.

…

 _A little smirk played at the edges of her mouth as she surveyed the pandemonium down below her. Maybe it would have been more appropriate for the ants to fall to their knees in acknowledgement of her power, but in its own way, fear was a perfectly valid expression for accepting that which was beyond them._

 _The plain, skintight black uniform that hugged her figure as she drifted slowly through the streets took in the firelight of the dancing flames filling buildings and enveloping cars and returned only darkness, only grim respect. It was so satisfyingly freeing, with no billowing cape or gaudy colors weighing her down, unlike the pathetic forms that she passed over._

 _Snapped batons and a bow cloven in two, strewn over fragile human bodies clad in white and green._

 _Pitted, blackened craters dotting the purple armor of a green-skinned alien, a last refugee of the red planet._

 _A crushed pair of glasses next to the metahuman, a freak science experiment who hopped between dimensions._

 _She felt thrill after thrill of satisfaction as she passed each and every conquest, eventually settling down on the ground in the middle of three particularly gratifying victories._

 _A weaker person might mourn the death of her blood, but the sight of the torn cape and charred red boots just made her turn up her nose and look away. All he wanted to do was "fit in" and be one of them, earning their praise by serving them rather than demanding it by ruling them. It made her sick._

 _It was a relief to finally be rid of the perfectly ordinary human, the one so determined to bring her down under false pleas of protection and sisterhood just to feel better about her own depressing, mortal existence. She was above them. Any measures to hide the unreachable extent of her godhood was pure insult._

 _The speedster was perhaps the greatest affront of all. Who were these humans, to think they could reach up and assume abilities far beyond their comprehension, far beyond their understanding? True power lay in the forces of nature, like the lightning bolt on his red, lifeless chest, or in the inimitable quality of her cells._

 _Not deigning to spare the still figures a second look, she stalked past them to a final body that, annoyingly, was still breathing. Bruised, bloodied, and beaten, but undeniably alive. Settling into a crouch, she reached down and grabbed a fistful of long blonde hair, matted with blood and debris though it was, pulling the unworthy garbage up to face her._

 _Clear blue eyes. Pale skin. Tattered remains of a red cape still on her shoulders. The crest of the house of El emblazoned on her chest, in a shape the puny humans referred to as an "S." Staring down into her own face, she couldn't believe that this weakling was ever a part of her. No matter, however. Infections can be expunged. She drew back her fist to crater her skull._

 _The weakling spoke, in a quiet, brittle voice. "I'm a part of you."_

 _Kara sneered. "Not for long." Her fist flew forward._

…

It was the hyperventilating that brought Alex back to reality.

Debris and sparks were still raining down from the hole Kara had made in S.T.A.R. Labs' ceiling, but they barely registered as Alex swung her head back to the bed, where Kara had awoken suddenly and now sat bolt upright. One fist was on her chest, while the other had already mangled the safety railing of the bed in its grip. Her eyes still glowing and sparkling in spurts like lights with a bad connection, Kara looked in absolute panic.

"Kara, Kara it's okay, you're okay," Alex began, rushing back and trying to envelop Kara in her arms, but Kara had started rocking back and forth, still fighting to breathe. She tried to pry her sister's hand off the piece of metal that had been the railing, but Kara's grip was far too strong.

"Alex," Kara gasped, "Alex, I—I killed you!"

"No, no Kara, I'm right here, right here," Alex pleaded desperately, completely at a loss as to what was happening. She could hear the rapid beeps from the medical equipment Caitlin had hooked up to Kara that signaled her sister's dangerously high, irregular heartbeat. "You're safe, you're safe," she continued, but Kara only shook her head furiously.

"Alex, I—," Kara gasped again, looking at her sister with wild, flickering eyes. "I can't—I can't breathe—I killed them! I killed everyone!"

"No, Kara, listen to me! It was just a bad dream! A nightmare! You haven't hurt anyone!"

" _She's here! She's me!_ " Kara pleaded desperately, nonsensically, as she shut her eyes and refused to face Alex. Alex tried putting a hand through her hair, against her cheek, anything to comfort her, but she was in complete terror. She could only recall a handful of times when she'd ever seen Kara remotely like this, but she didn't know what to do this time. She didn't know what was making her react this way, what was going through Kara's mind, and Kara wouldn't or couldn't tell her.

Caitlin rushed into Alex's field of view. Putting her hand over Kara's fist, the one pressing against her chest, she said, loudly but calmly. "Kara, look at me."

"Caitlin, be careful," Alex warned, knowing that Kara's grip on herself, including her heat vision, was tenuous.

Without looking Alex's way, Caitlin nodded to signal she had heard but only tightened her hand over Kara's. "Kara. Look at me," she repeated.

Still gasping for air, Kara slowly opened her eyes and looked at Caitlin, her eyelids in a squint as sparkling energy flickered underneath.

"Good," Caitlin nodded, acknowledging the enormous effort it was clearly taking Kara just to face her. "Now look around this room. Tell me five things you see."

"Wh—what?" Kara asked, so distressed that she seemed to be having trouble comprehending the instruction.

"It's real easy," Caitlin told her, in a soothing, reassuring voice. "Can you do that for me? Just tell me five things you see in this room."

"I—I can't—"

"Yes, you can," Caitlin replied quickly, cutting her off gently. "Don't think about anything else. Just five things you see."

"I—," Kara started, bewildered. She took this moment to actually glance at Alex, almost asking silently if she had heard Caitlin correctly, and Alex gave her a small smile and nod to reassure her. Swallowing, still gasping, Kara's head swiveled around the room. In a brittle voice, she began, "Uh, there's—there's that medicine cabinet over there."

"Good," Caitlin encouraged. "Four more."

"And—and there's a flashlight on that table."

"Right. Three more."

As Kara continued to struggle breathing, Alex's instincts screamed for a more direct solution, but she could also tell Kara was fighting desperately to regain control, and she trusted Caitlin to help her get there. "The rolling chair, under the desk." Caitlin nodded, never taking her eyes off her patient. "The—the notepad on the desk. And—and the big computer monitor out in the lab," she stammered, tilting her head in the direction of the clear glass through which they could see the main lab.

"Good, Kara. Now, what are four things you feel?" Caitlin continued.

"I…feel?"

"Yeah, right now. Four things you can physically feel."

Kara's rocking had slowed, and her breathing had become slightly less shallow. Alex also noticed the rhythm of the beeps indicating Kara's heart rate, while still too irregular, was not as frantic as before.

"I feel…the cot that I'm sitting on." Again, Caitlin nodded her encouragement. Hesitantly, Kara turned her head to look at Alex, who noticed that her eyes were flickering more weakly. She nodded as well, and Kara continued. "I feel your arm around my shoulders," she said, looking at Alex. "I feel your hand over mine," she also said, turning to Caitlin. "And…and I feel the metal in my grip," she finished in some surprise, seeming to have noticed for the first time the rail she had twisted with her other hand. Slowly, she let go.

"That's perfect Kara. Now tell me three things you hear." By now, Kara's breathing had slowed even more, her speech no longer coming in between gasps. Just having something else to focus on, something to disengage her from whatever demons filled her mind, was helping Kara to regain her sense of self. Still, she seemed desperate for someone else to lead her, so she continued to oblige Caitlin, more calmly than she had before.

"I hear the beeping of my heart rate monitor," she began, and Alex registered that the rhythm had slowed still further. Kara's head tilted upward. "I hear sparks from the wires in that hole in the roof." She closed her eyes, not out of fear anymore, but apparently to focus her superhearing. "And I can hear birds outside the hole flapping their wings."

"You're doing really well, Kara. Now tell me two things you smell."

Kara hadn't reopened her eyes. "I smell singed metal from the hole. And I smell Alex's shampoo." Her breathing was completely normal now, and the heart rate monitor's rhythm was steady.

"That's good, Kara. Really great job," Caitlin encouraged, smiling slightly. "Last one now. Just focus, and tell me one thing you taste."

"Blood," was Kara's immediate reply. "I bit myself when Psi punched me." With that last comment, Kara opened her eyes. No sparkling, destructive energy, just the same kind eyes Alex had always known. And they were filling with tears.

It was clear Kara remembered everything. She knew what had happened to her in the field, how she'd been overpowered, and how she'd ended up in such a state. Whether she was relieved that she had finally found a place of calm after all that, or embarrassed for how crippled she had been in these past few minutes, Alex wasn't sure, but she quickly pulled her sister into a tight hug, offering her chest as a place where Kara could hide her face as she sobbed. Without loosening her hold, she turned her head to Caitlin. "Thank you," Alex mouthed.

Caitlin nodded. As Alex tightened her arms around a shaking Kara, the doctor bowed her head, closing her eyes a moment as she let out a long breath.

…

Felicity timidly made her way back to the med bay, hoping to check up on Kara without accidentally setting off any heat vision-fueled destruction. Of course, the hole Kara inadvertently blasted in the ceiling had not gone unnoticed, but it had been clear that Caitlin and Alex were the only ones Kara's senses could handle, so Felicity had kept away. Now, however, she wanted to check to see if things had subsided or if an evacuation of S.T.A.R. Labs was in order.

Walking down the hallway of S.T.A.R. Labs, she saw Alex and Caitlin leaning tiredly on opposite walls, inadvertently looking like guards restricting access to the med bay and the Kryptonian inside. "Is Kara okay?" Felicity asked, striding up to them.

"Yeah, she's okay," Caitlin confirmed, before tilting her head to clarify. "I think. As far as I can tell, she suffered a panic attack."

"Psi has that effect on people," Alex said, "but that was the worst I've ever seen. Kara could barely even talk. It sounded like she had some kind of nightmare before waking up."

"Is the nightmare what triggered her to react that way? Did Psi plan for that to happen?" Felicity asked.

"Maybe, maybe not. I can't say if Kara's mind was more vulnerable, whether her intense reaction to Psi was because Rainbow Raider weakened her mentally first, but a nightmare doesn't necessarily lead to a nocturnal panic attack. Honestly, there isn't always _any_ reason a panic attack hits," Caitlin replied. Sighing, she continued, "There's so much we still don't understand about the brain, human or alien. Add in some metas, and it's all just a mess."

Felicity shook her head, glancing significantly in the direction of the patient Caitlin had just helped. "How do you even prepare for something like _that_?"

"Kryptonian mental health was not covered in med school," Caitlin admitted wryly. "She fell asleep a little while ago. Where are we in finding Barry?"

"Nothing yet," Felicity reported reluctantly. "Kendra's flyover of the city didn't turn up anything. Iris and Joe are coordinating a section-by-section sweep of the city now."

Caitlin nodded. "Keep me up to date. I'll see what I can do to help in a little while. I just need a break."

"Of course. You've done so much," Felicity assured her. "Although, you should know that something seems to be interfering with our JL frequency. I've lost contact with a bunch of our members. I can't raise Oliver or anyone from the Bunker. No one's answering at the DEO. Leaguers in other cities have gone quiet too."

"Everyone?"

"Not yet. I've still got Kid Flash and Superman doing separate sweeps outside of the city to look for Barry, but Hawkgirl's comm just went down also."

"Let me see what I can do," Alex began, straightening up from the wall. "I'll see if I can get to the DEO."

Felicity raised a hand to stop her, smiling reassuringly. "Don't worry, Alex. Winn's made me familiar with the DEO's systems, so if I make a breakthrough, I'll let you know. Kara's your priority right now."

Alex hesitated, clearly torn between family and duty, but Felicity was confident Kara would outweigh the rest of Alex's concerns. She was right. "Okay," Alex replied, nodding. "Thank you, Felicity."

"Anytime."

Caitlin nodded as well. "Alright. In the meantime, everyone stay alert until we figure out what to do next."

…

Kara didn't want to wake up.

Crying her heart out into Alex's DEO uniform had taken the last bit of strength out of her, and as cathartic as it had been, she was completely worn out afterwards, passing out almost immediately after the tears had stopped. Sleep following something like that was peaceful, dreamless, and she wanted to stay there.

Awareness crept into her mind, however, and as she slowly, hesitantly opened her eyes, her mind began catching up with the situation, prompting the need for an urgent question.

Alex was in a chair next to her, absentmindedly staring at the floor, lost in thought. Kara shifted slightly on the bed as she woke up a bit more, and her sister's head immediately snapped towards the movement. "Kara!" she said, in a relieved voice. "How are you feeling?"

"Where's Barry?"

Alex sighed. "We're not sure. When your comm went down during the mission, his did too. Pretty soon, we lost visual contact."

" _What_? We need to find him," Kara insisted, starting to get up.

"Hey, hey, hey," Alex replied, rushing over to put her hands on Kara's shoulders. "We will. We're sweeping Central City as we speak, and we've got Leaguers expanding the search."

Kara still wasn't convinced. "How long have I been out?" _More specifically, how long has he been missing?_

"A few hours," Alex said. Kara was about to reply that a lot could happen in that time, but Alex cut her off before she could start. "Kara, Barry's not helpless. Until we find him—and we _will_ find him—he can take care of himself. You should take it easy."

Despite Kara's instinct to protest more, Alex had that look in her eyes whenever she was seriously worried about her, and she had a painfully clear memory, not only of her earlier panic attack, but of how terrified and helpless Alex had looked during the episode. Not wanting to stress out her sister even more, Kara reluctantly allowed Alex to push her back down onto the bed, although unable to resist letting out a sigh of frustration.

"Seriously, how're you feeling?" Alex asked again.

"Like a moron," Kara replied, bitterly. "I've fought Psi before. I can't believe I let her get the drop on me."

"Hey, don't be so hard on yourself. Psychic powers are tricky, Kryptonian or not," Alex reasoned. "Besides, you were technically hit with a one-two mind-altering punch out there."

"Oh yeah. Who was that other guy?" Kara inquired. Alex gave her a quick rundown of Rainbow Raider's powers and what she knew from Caitlin about how his previous encounter with Barry had gone.

"So that's the meta that made Central City afraid of Barry," Kara mused quietly after Alex had finished. "He told me about it years ago, but I never realized…," she trailed off. After a couple moments thinking to herself, she arched an eyebrow and looked at Alex. "What kind of name is 'Rainbow Raider'?"

Alex chuckled quietly. "Caitlin's idea. She's a little sensitive about it."

"She is _not_ good at picking names."

"Amen to that." They lapsed into a comfortable few seconds of silence before Alex spoke again. "In fairness to Caitlin, she was able to help you ground yourself after you woke up."

"Yeah," Kara agreed, though she turned her head away from Alex, still feeling a sense of shame and humiliation at how she had lost control, how her physical senses were convinced she was suffocating. That kind of vulnerability was not something Kara, and especially not Supergirl, enjoyed letting anyone see.

Of course, being her sister, Alex picked up on her emotions. "You want to talk about it?"

Kara didn't reply at first. Unspoken, but understood between the two of them, was Kara's discomfort with the idea that she'd had a panic attack. She'd had them before, when she was young and had just arrived on Earth, and even during her first encounter with Psi, but past occurrences made it no easier for Kara to come to terms with them. She knew there was no reason for her to feel embarrassed, that her friends and family did not and would not think any less of her for them, but the idea of accepting them, particularly as a superhero, was less of a concrete decision and more of a continual, grinding process.

The experience bubbled up old thoughts and feelings of which she was definitely not proud, and her dream just prior to waking had felt so vivid, so real, that she had been convinced, however briefly, that she'd murdered the people she loved and cherished the most. In the end, she knew she wouldn't, or couldn't, keep this a secret from Alex for long anyway, so hesitantly she began to speak.

"It was like I was on red K again," Kara said, quietly. "The smug superiority. The violence. The rage. When Rainbow Raider hit me with his powers, everything came rushing back."

"That wasn't you, Kara. It wasn't you when you were on red K, and it wasn't you now."

"Those feelings didn't come from _nowhere_ , Alex," Kara retorted, turning her head back to face her, willing her to understand with her eyes.

"Just because you thought them, that doesn't mean you'd ever act on them."

Kara sighed. "It gets worse. After Psi hit me with her psychic pulse, it's like all my rage got flipped into fear. I went from feeling the rage to seeing all the devastation I could cause from that rage." She paused a moment before continuing. "Before I woke up, I was having this really vivid dream of all the damage I could do and all the people I could kill. Clark was dead. Barry was dead. You…you were dead. Because of me."

Alex took Kara's hand in both of her own. "It won't happen."

"It _has_ happened! Or, something like it _could've_ happened, if you and J'onn hadn't stopped me the first time!" Kara was on a roll and needed to get everything out. "I was jealous of Clark, for a long time, before I became Supergirl. I was jealous that he could openly use his powers and be greeted by adoring crowds while I just plodded along as Kara Danvers." She sniffed as her eyes watered slightly in shame. "I hated metahumans when they first appeared after the particle accelerator explosion. I hated that they were hurting so many people with their new powers. And…and I hated you, when I first came to Earth. I didn't ask to be stuck with humans."

Alex shook her head. "It was a long time ago, Kara."

"I just…I just feel like there's a part of me that I'll forever have to guard against. That there's a part of me that'll always be a threat to the people I love. The feelings, those are scary enough. With my powers behind them?" Kara shook her head, unwilling to complete that line of thinking. "The last time Psi hit me, my worst fear was seeing Krypton die again. But now? I just have so much more to lose now."

Seemingly unable to come up with a response, Alex leaned over and pulled Kara into a hug. "Kara, I can't imagine what this has been like for you, but I'm going to tell you the same thing I told you after the red K." She paused a moment to squeeze a little tighter. "Hormonal teenager or not, alien or not, you're my sister. I love you, no matter what."

A couple tears spilled out of Kara's eyes, and she couldn't think to do anything other than hold her sister close. She would've stayed like that forever, but a jarring alert sounded off, accompanied by Felicity's urgent voice.

"Everyone, get to the main labs. We've found something."

…

Kara couldn't understand what she was seeing.

Streaks of orange and yellow flared through city streets, up and down buildings, over and under freeway overpasses, the sheer number of city cameras Felicity had tapped into to watch the action making her head dizzy. Occasionally, a red-and-blue smear would try to enter the fray, only to get smacked back out.

"What's going on?" Alex asked, confusion evident on her face.

"We got an urgent message from Wally," Felicity explained tensely, "but when I got his location, this is what I found." She pressed a button, but all anyone could hear in the labs was static interference. "Whatever's happening, Wally can't seem to talk anymore."

"But that's Clark!" Kara exclaimed, pointing at the colorful blur trying once again to force himself into the storm of lightning blazing through the streets. "That's Metropolis! Get him on the line!"

"We've been trying," Caitlin interjected. "Wally's communicator is responding, but he's not talking to us. Clark's communicator isn't responding at all."

"Another signal I lost," Felicity muttered, through gritted teeth.

"I've got to get out there," Kara said, turning partway towards the S.T.A.R. Labs exit. "I've got to help."

Harry stepped in front of her. "Even at your top speed, you wouldn't get to Metropolis in time to make a difference."

"I can't just sit here."

"Wait, look!"

Kara whipped her head around just in time to see Clark finally time his assault correctly, tackling someone in the middle of the electrical storm raging through the streets of Metropolis. Immediately, Wally dropped out of superspeed, falling forward and rolling over and over until he was facedown, his suit battered and torn.

"Wally? Wally, can you hear me?" Caitlin urged into the microphone at the main lab's center console. Two camera feeds enlarged on the screens in the lab, the one on the left focusing on Wally, the other on the right on the mess of debris and dust that was Clark wrestling with whomever he had tackled.

Slowly, they watched Wally reach towards his ear, adjusting his JL communicator so he could speak. Finally, they heard him, weak and out of breath. "Lock it down," he muttered.

"Wally, what're you talking about?" On the right screen, Clark was on his feet, desperately trying to block strikes wreathed in lightning. Her eyes narrowed, Kara strained her own sense of superspeed in her attempt to follow the action. Clark was clearly trying to respond to the barrage with his own enhanced speed, but his opponent was outmatching him at every turn, every streak of light causing him to wince and jerk. Kara's stomach turned to ice as she began getting a vague but alarming picture of what she was really seeing.

On the left screen, Wally pushed up to his hands and knees, head bowed wearily. "We need to lock down S.T.A.R. Labs, the Bunker, the DEO, everywhere."

"We lost contact with them. Wally, what's going on?" Caitlin urged.

On the right screen, flashes of green could also be seen accompanying the lightning through the cloud of debris, Clark struggling to stay on his feet as strikes came from virtually every angle and every direction. His face was a sheen of sweat and pain as his veins glowed sickeningly. Whoever was attacking him had Kryptonite. "No…" Kara whispered.

"It's Barry," Wally croaked. "He's taking out Leaguers!"

With a green-and-yellow-streaked uppercut, Clark's head snapped backwards and his body flew across multiple camera views, and Barry's blank face, the cowl dislodged at some point during the fight, came onto the screen through the dust. With horror, Kara could only watch as Wally slowly got to his feet, clearly beaten past the point of resistance. After one blink, Barry was at his side and Wally was back on the ground, unconscious. After a second blink, Barry, Wally, and Clark all disappeared from the camera feeds.


	3. Chapter 3

Confusion and shock threatened to overwhelm Kara as she stood rooted to the spot. Her senses went numb even as Caitlin scrambled around the main console, practically slamming a command into the controls. Immediately, an alert went off inside S.T.A.R. Labs. "Stand by for security lockdown," intoned an automated message.

"Looks like we upgraded just in time," Harry mused.

"What…what's happening now?" Kara stammered.

"A high-energy field is going up around S.T.A.R. Labs. Completely spherical, even through the ground underneath us. It should be able to block even Barry from phasing through," Harry explained.

"But that'll cut us off from helping him!"

"Unfortunately, we have to start by helping ourselves," Caitlin interjected, bringing up new feeds on the lab screens. Four faces appeared.

"Jay, Jesse," Caitlin said urgently, addressing the two speedsters who had shown up on the left hand screens, "Barry's gone rogue. We need you two in the Speed Force. Make sure he doesn't try to alter the timeline."

Despite the lack of information, the speedsters immediately grasped the severity of the situation. "Copy that. Keep us informed," Jay replied. Then both screens went dark.

"Cisco, Gypsy, stay alert in the multiverse," Caitlin then said, turning to the right-hand screens. "Make sure to contain any damage to Earth-1."

"Forget that, I'm coming back to S.T.A.R. Labs! I can help!" Cisco urged, clearly wanting to figure out what was wrong with his friend.

"Cisco, I need our speedsters to keep the Speed Force safe. Without them, you and Gypsy are the only ones protecting the multiverse."

"Don't worry, Ramon," Harry jumped in. "We'll figure this out."

"We'll get Barry back, I promise," Felicity added.

Cisco still hesitated. "Cisco," Caitlin finished, soft but firm, "I need you to do this."

A final pause of reluctance, but then Cisco nodded. "Roger that, Dr. Snow." His screen and Gypsy's went dark.

"It's lucky Barry hasn't hit our Leaguers on other Earths," Felicity remarked.

"Let's hope it stays that way," Harry said.

"So what now?" Alex asked.

"Now," Kara said, "I go out and find him."

"Kara, wait," Caitlin replied, putting up a placating hand. "We don't even know what's going on, and he just beat Clark."

"I'm faster than Clark is. James said so himself, and he would know!" she insisted, turning to walk out of the lab.

"But you're not faster than Wally," Caitlin countered calmly, stepping sideways to block Kara's path. "And he got taken out, too."

"I don't care! I have to find him!" Again, Kara tried to push her way out of the lab without resorting to her powers. Felicity reached out and softly laid her hand on her arm.

"We will, Kara," Felicity soothed. "But we need a plan. With the communicators down, we're on our own."

"I can't do nothing!" Kara's emotions were bordering on frantic, and her head swiveled from side to side, trying to will the others to understand.

"Kara," Alex finally said, taking her sister's head in both hands and forcing her to look Alex in the eyes, "we will save Barry. I promise you. It will take time, but we will save him."

Every alarm bell and panicked thought in Kara's head screamed in disagreement, but the conviction in Alex's eyes was such that Kara couldn't help believing her. Her distress lightened by a tiny fraction. For now.

Reluctantly, she nodded, taking a breath. _Hang on, Barry. I'll get you out of this._

"Well, for starters," Felicity began, eager to get something going before Kara changed her mind, "clearly Barry got Kryptonite somewhere. Whatever we end up doing, we can't have Supergirl be vulnerable. She's the hardest hitter we have left."

"Actually, Winn sent us a design for a new Supergirl suit that's supposed to protect her from Kryptonite radiation," Caitlin said.

"Right, he told me about that," Alex put in. "It has integrated technology from the suits Non and his followers wore when they attacked National City."

"Cisco had a prototype made, but I don't think he finished it before he left with Gypsy." Caitlin turned to Harry. "You think you can complete it?"

Harry nodded. "Anything Ramon can do, I can do better," he declared, walking out to get to work.

Rolling her eyes slightly at that, Caitlin turned back to study the video feeds they were able to record of Barry's fight with Wally and Clark, playing on multiple screens on a loop around the lab. "Now we just need to figure out why Barry's doing this."

"It's obvious, isn't it?" Kara insisted. "He's being coerced somehow, or even controlled! Psi or Rainbow Raider got to him!"

"Probably," Caitlin replied, matter-of-factly. It was a sign of the crazy times they all lived in that this was, if not a mundane occurrence, then certainly not an unprecedented one. "But we need to figure out exactly what's happening. Maybe they were nearby pulling the strings."

"You think there may be clues in these feeds?" Alex asked, as she and Kara moved to join Caitlin and Felicity at the console.

"It's all we have to go on for now."

…

An hour of repeatedly scanning the feeds later, all four women were visibly frustrated.

"Barry's alone out there. I don't see Psi or Rainbow Raider or anyone," Felicity complained, clicking through her video of the Metropolis fight frame by frame for the tenth time.

"Well, at least we know he's knocking out Leaguers, not killing them," Alex replied. "If he'd wanted to kill Wally or Clark, he could have. The fact they all disappeared from the cameras means he sped off with them somewhere."

"He's so fast now," Caitlin muttered, as the looping video replayed Barry and his speed completely dominating Superman. "He managed to shut down the League across the whole country in one day."

"Barry's so fast, he could have easily taken out Clark's JL communicator at some point during the fight," Kara added. "Wally must have been the only one fast enough to stay ahead of him, at least for a little while."

"Which is why we were able to stay in touch with him even with the rest of the League dropping off without a word," Caitlin continued, nodding in agreement.

"Okay, but what does all that tell us?" Felicity wondered.

"It means someone wants to destroy the League," Kara replied. "Even if they're not killing us, clearly someone or something's trying to remove us."

"Yeah, but I can't find them anywhere," Felicity countered in frustration. "Even kidnapped, you'd think a Kryptonian or Martian life sign would be easy to detect."

"There must be some sort of shielded bunker or prison somewhere," Alex reasoned. "With Barry's speed, it could be anywhere in the world."

An annoyed sigh passed through the four of them, staring at a still shot of Barry's face, uncovered by the cowl and advancing on Wally. "It doesn't _look_ like he's acting out of rage, the way you'd expect if Rainbow Raider hit him," Caitlin admitted.

"And you're sure there're _no_ weird signals detected? Something else that may be invisible to us that might be affecting him?" Kara asked.

"I've done a full electromagnetic sweep using S.T.A.R. Labs' satellite," Felicity replied, dejected. "Nothing."

"What about psychic energy?" Kara persisted.

"We've already looked for Psi," Alex pointed out. "She's not there, and her effective range is short."

"Can we scan for psychic energy anyway?" Kara asked, desperately. "There has to be _something_."

"Hmmm," Felicity said, starting to type into the console. "Tracking psychic energy is pretty difficult, especially since every source of it is different. We may not see anything if we don't even know what to look for."

"Can you try? Please?" Kara continued, pleading with her eyes.

Felicity nodded, shrugging. "I'm out of ideas, so let's give it a shot," she said, typing furiously. Bars started sweeping across the image of Barry's face as Felicity's various filters went to work. After a tense half-minute, the screens returned the processed image to show any detected anomalies.

Everyone froze. Felicity's program had regenerated the stoic image of Barry's face in black and white, with one exception. There, in the center of his forehead, was a circular pattern of pink, sparkling energy. They had seen something like that only once before, during an alien invasion that had threatened the entire world.

"Oh, frack me," Felicity muttered.

She didn't consciously register making any decision. Her brain saw the image on the screen, and the next thing she knew her legs were striding for the exit, cape billowing behind her.

"Kara, stop!"

"It's Dominators, Caitlin! We can't wait!" Kara was legitimately on the verge of bulldozing past the doctor on her way out of the labs.

"What's going on?" Harry asked, reentering the lab.

"Dominator mind control," Alex updated him. "That's why Barry's acting the way he is."

"Lovely," Harry muttered sardonically.

"I'm leaving," Kara declared, making for the exit again.

"Kara, we've been through this," Harry lectured at her. "You saw Barry take down Superman _and_ Kid Flash. You're not fast enough. You can't just—"

"Then give me a plan!" Kara snapped, finally at the end of her rope with just _sitting_ and doing _nothing_. Barry was under Dominator mind control, the entire League was under attack, and she needed to do _something_ about it. She glared around the room. "I'm open to anything, but I am not just going to wait without any idea of what to do next! Barry needs me. _Now_."

A small part of Kara's brain understood things from everyone else's point of view and felt guilty for yelling at them like this, but her urgency was at a breaking point. Her thoughts had squarely been on saving Barry up to this point, and while that urgency remained, the stakes had suddenly become much, much higher with the real threat now revealed. Luckily, she saw Caitlin sigh and view her not with pity or defensiveness, but a perceptive understanding of what Kara must be feeling.

Caitlin started walking towards a blank wall of the lab. "There might be one option," she offered reluctantly.

"Snow…," Harry began, warningly. Caitlin ignored him and stopped in front of a seemingly random location at the edge of the lab. She pressed her hand against an innocuous, outwardly random tile in the pattern of the wall, and suddenly a secret compartment opened up in the tile right next to it. Reaching inside, Caitlin pulled out a vial of red liquid. "Absolutely not!" Harry cried.

"Harry," Caitlin countered, a warning in her own voice, "she has a right to at least consider her options."

"What is that?" Kara asked immediately, refusing to be referred to in the third person when she was standing right there.

"It's called Velocity 9," Caitlin explained, holding up the vial. "It's a serum designed to enhance a speedster's connection to the Speed Force, temporarily boosting his or her top speed."

"Call it what it is, Snow," Harry interrupted. "It's a drug. It's a speed drug."

"Which Harry and I developed together," Caitlin added.

"Yes, for _speedsters_ ," Harry shot back.

"Wait, so how does that help Kara?" Alex asked.

Harry gave Caitlin an intense glare, as if daring her to say any more, but Caitlin was not intimidated. "A while ago, a woman named Eliza Harmon got ahold of the drug and ended up using it. She became a speedster, despite being a human with no connection to the Speed Force."

"Are you serious?" Felicity asked, shocked and slightly aghast.

Caitlin nodded. "At the time, she was even faster than Barry."

Harry's attitude suggested to Kara that there was more to this story. "What happened to Eliza?"

"She died," Harry answered harshly. "Her body couldn't handle the serum and literally disintegrated right in front of Barry. Nothing left but her suit."

Silence prevailed over the group as the horror of the incident washed over everyone. Kara could still see where Caitlin was going with this, however. "I'm not human."

Caitlin shook her head, seeming to have expected Kara to catch on quickly. "No, you're not. Your Kryptonian biology is way tougher than ours, so even without a connection to the Speed Force, you may still be able to take it without it killing you. You'd be able to keep up with Barry for a while."

Harry scoffed. "Even if she doesn't die, that's not the only disaster waiting to happen with this drug."

"And what does _that_ mean?" Alex interjected.

"It means she'll go crazy!" Harry snapped.

"Harry!" Caitlin reprimanded.

Harry closed his eyes and took a breath, seeming to acknowledge that he had chosen his words poorly. When he opened them again, he looked directly at Kara. "Eliza was perfectly healthy before taking the V-9. After she took it, she developed a split personality. The drug destroyed her mind."

Kara curled her hands into fists to keep them from shaking. _First Psi, now this?_

"Besides, it's a cheat," Harry insisted. "A shortcut to get faster."

"Harry, Kara's not a speedster," Caitlin shot back. "It's a question of Kryptonian biology, not Speed Force connection. Her natural speed has an upper limit."

"Making that drug was one of the greatest mistakes of my life," Harry persisted, in a sober but dogged voice, "and in the end, not even Barry used it. Kara, it's too dangerous. For us and for you."

The sincerity of his voice struck her, and for a moment she hesitated, turning to Caitlin with a silent question in her eyes. _Will this work?_

Caitlin shook her head. "I can't know for sure, Kara. I believe your biology would protect you, but everything Harry's said is also true. Under any other circumstances I wouldn't recommend this, but it's your decision."

What a decision it was. Without more information, more tests, every part of Kara's rational being was telling her to find another way. The emotional side of her, however, focused not just on Barry, but on Clark, and on all the Leaguers who could be at the mercy of homicidal aliens. How long before they used Barry to sweep away all resistance? How much longer could the Girl of Steel do nothing?

She turned to the person she trusted above all else. "Can you look at it? Tell me what you think?" she asked Alex.

Nodding, Alex understood immediately and walked over to Caitlin, holding out her hand. "Let me examine this serum before we decide anything."

Too late, Kara realized she may have inadvertently insulted Caitlin, unwilling to trust her opinion on something she helped create, but fortunately Alex picked up on that as well, following up, "You're the expert on Barry's physiology, but I know more about Kara's. It'll take both of us to give her as much information as we can." Unable to argue with that logic, Caitlin handed over the vial, and Alex headed to the bio lab.

"In the meantime," Caitlin then said, as Alex walked away, "we can still make other preparations. Harry, is the suit almost ready?"

"This is a bad idea," Harry began, clearly unwilling to give the conversation a rest.

"Harry," Caitlin repeated, calmly and evenly.

Harry sighed. "Yes, it's almost ready."

"Good. Keep me posted." Caitlin turned to Felicity, still seated at the desk while watching the ping-ponging conversation the whole time. "Can you track the origin of the Dominator signal?"

"I think so," Felicity replied, swiveling on her chair back to the controls. "We've seen this type of signal before from the last invasion, which is probably why the satellite was able to see it at all. Should be able to trace where it's coming from."

"Get working on it." Caitlin's head turned to face Kara, a silent question of her own now. _How's that for a plan?_

Kara gave her a small nod of gratitude. "Thank you," she mouthed.

…

"This suit's design and material will protect you from Kryptonite's long-range effects. You won't feel weak or nauseous, just like Non's suit did for him."

"What about direct attacks?"

Harry hesitated. "Normally, your other abilities would be more than enough to counter anyone trying to physically hit you with Kryptonite."

"Against Barry?" Kara persisted.

"Well," Harry continued, "with all due respect to your nickname, from what Caitlin's told me, Barry learned how to punch steel just months after getting his powers." He paused, seemingly trying to remember exactly how Caitlin had explained it. "Something about a meta that could turn his skin into metal. Barry's only gotten stronger since, and now that he's got Kryptonite behind those punches…"

"…I should be careful," Kara finished for him. "Got it." Observing the suit Harry had finished for her, Kara could certainly appreciate the workmanship he, Cisco, and Winn had put into it. It was a full, dark blue, one-piece uniform that covered from neck to toes, closer in design to Aunt Astra's militaristic style rather than her own skirt-and-leggings combination, with reinforced padding around the thighs, knees, shoulders, forearms, and elbows to handle the stress of fights. The sleeves ended in straps to be looped around the meat of her thumbs, in a similar style to her normal suit. An armored belt broke up the upper and lower sections, and the S-shield was heavily stylized in a cool, almost glowing blue. Attached to the shield and running both around the neck and down the back was a dark red cape, the hue matching padded, fitted calf boots.

"Honestly, an upgrade like this was long overdue," Harry said, observing his handiwork. "I don't know why you and your cousin don't wear suits like this all the time to protect yourself from Kryptonite."

"Because suits like these are for battle," Kara quickly answered. "For war. That's not what the House of El represents." Her admiration for the suit's technical and aesthetic qualities didn't mask the bitter taste in her mouth at the idea of wearing it. As Harry didn't seem to have a retort, however, she continued to acquaint herself with it, her eyes drifting to the top. "What's that for?" she asked, pointing at the face piece.

"That will protect your mind from any external psychic threats," Harry explained, taking it down to show her. It was a minimalist piece of tech, attaching around her forehead and under her chin while leaving the rest of her head and face clear. "We don't know yet how Barry got mind-controlled, but we need to make sure you're safe, whether the psychic attack comes from Dominators or metas."

Kara nodded. "Thank you, Harry," she said, inflecting her voice to let him know she appreciated the custom protection and the work that went into it. "Really."

"You're welcome, Kara." With that, Harry turned to return the headpiece to the dummy on which the suit was currently draped, and Kara heard a knock.

"Hey, can I talk to you?" Alex asked, walking in.

"Sure," Kara said. "We can go to the med bay."

"Don't bother," Harry interjected, already walking past them towards the door out of Cisco's work lab. "I need to update Caitlin anyway." Without another word, he left them alone.

Kara turned to Alex. "Will it work?"

"I…I think so."

"Good enough for me."

"Kara," Alex began, passing the V-9 between her hands, "just because this serum can make you fast enough to stop Barry, that doesn't mean it's worth all the other risks. Caitlin and I have no idea what kind of side effects you'll suffer with your physiology. Physically _or_ mentally." She paused a moment before finishing, "Barry wouldn't want you endangering yourself like this."

"This isn't about Barry," Kara snapped, weary of yet another "it's too dangerous" argument.

Alex gave her a look and crossed her arms. "You can't lie to me, Kara."

Kara held Alex's eyes for a moment before dropping them and sighing, slightly chastened. "Okay fine, it's not _just_ about Barry." Looking back up, Kara saw that Alex had softened, accepting her unspoken apology for trying to brush past the issue. "I promise Rao, I'll do whatever I have to do to save him, but it's more than that."

"Is this about your panic attack?"

 _Having a perceptive sister is so annoying_ , Kara thought. "I just…," she started, grudgingly, "…I _need_ to make this right. While I was knocked out on the ground, Barry got mind-controlled, and we saw him take out Clark and Wally. I've just been sitting here," she added in frustration, flipping her hands downwards to emphasize her point, "and meanwhile he probably took out J'onn and Oliver and anyone else who could beat him, too."

"We don't know that for sure," Alex shot back.

"S.T.A.R. Labs was the only JL hub to install the new security upgrades, and we still got lucky Barry didn't come after us, activating them as late as we did. None of the others could be defended like ours. That has to be why we can't bring them up on comms." She had to make Alex understand. "I'm the only one left with even a chance."

"Kara, this isn't your fault," Alex urged. "Getting ambushed by Rainbow Raider. Getting ambushed by Psi. Your reaction afterwards. No one blames you for this, and rushing out to prove something to yourself is just not a good idea."

"Alex, I'm one of the founding members of the League," Kara replied, willing her sister to understand, "and the League is in danger." She took a couple steps forward and covered Alex's hand, the hand that held the Velocity 9, with her own. "This is my responsibility."

Kara wasn't sure there was ever a moment in her life on Earth that Alex didn't worry about her in one form or another, but at least this time she could see Alex respect her decision. Alex's hands shifted to grip Kara's. "Well, you're not going at this on your own."

"I never said I was," Kara quipped, rolling her eyes and chuckling. Putting on a mock pout of annoyance, she needled her sister. "Geez, you never listen to me," she sighed.

"Shut up."

…

Alex walked into the main labs to find Caitlin, Felicity, and Harry hunched over the console. Caitlin and Harry turned to look at her, a silent question in their eyes.

"We're a go," Alex said. Caitlin nodded. Harry tightened his jaw but said nothing.

"There," Felicity said, pointing to a blinking dot on her screen. Everyone else turned to the console. "That's where the Dominator signal is coming from."

"Where is that?" Harry asked, squinting his eyes.

"Somewhere in the middle of the Great Basin Desert."

"Not a bad place to hide," Alex acknowledged. "The DEO's used the desert to conceal plenty of sensitive secrets."

"Can you disable it from here somehow?" Caitlin asked.

"No," Felicity replied in frustration. "And even worse, I recalibrated the satellite to look for alien signals, and there're jamming fields all over the place. National City. Star City. A new one just went up in Metropolis, too."

"What about Barry?" Caitlin asked. "Can you find him?"

"He must be moving too fast," Felicity replied again, "and obviously he must have ditched his JL earpiece a long time ago. I have no idea where he is."

"But if we destroy the source of that signal, that should free Barry, right?"

"If our history with the Dominators serves."

"There's no way it could be that easy," Harry insisted.

"Well, I guess we're about to find out," Kara interjected, walking into the labs.

Alex turned around and immediately saw what Kara could be like if she stood for war, for rule and conquest, and not peace. The full-body one-piece suit, the stylized S-shield, the glowing face pieces and armor-like padding, the dark red waves on her back that seemed to be part cape, part cloak. Alex knew it was all the same to Kara's Kryptonian physiology, but the various pieces of the outfit nevertheless seemed to weigh more heavily on her, giving her a more serious, almost cold bearing. It was hard thinking of her as Kara Danvers, rather than as Kara Zor-El.

Then she caught Alex staring and rolled her shoulders awkwardly in response. "It itches," she complained, making a face. Alex laughed.

Harry stepped forward and gently took the Velocity 9 vial Kara was holding in her hand. "Once again, I'd like to protest this," he persisted.

"You said it yourself," Kara countered. "Taking out that Dominator transmitter can't be as easy as it looks. We have to assume Barry will be defending it."

"And in that case, the V-9 is Kara's only chance," Caitlin finished.

Sighing, Harry walked around behind Kara and gently lifted one corner of her cape at her left shoulder. Pressing a button, he opened a small compartment hidden in Kara's shoulder pad, inserted the vial, closed the compartment, and then let her cape fall back into place, completely hiding it. "That compartment includes a miniature delivery system encased in lead," Harry explained. "If you activate it, a small needle laced with low levels of Kryptonite will inject the V-9 into your bloodstream and then retract back into the lead casing."

"How can I activate it?"

"Your shoulder pad material will recognize your fingerprint. Just touch any finger to it, and the system will deploy."

Kara nodded. Felicity stepped forward and handed her a JL communicator to place in her ear. "We'll be with you the whole way. I've modified this to cut through the Dominator jamming fields that we've seen."

Taking the earpiece, Kara flipped her hair back to insert it, seeming to catch what everyone was thinking as she did so. "I won't use the V-9 unless I have to," she reassured them, looking specifically at Alex.

"Just be careful," Alex urged.

"I will."

A minute later, the S.T.A.R. Labs group stood gathered around their screens as Kara flew out and up away from the building. Caitlin entered a command at her station, and a small circular hole opened up at the top of the protective, spherical force field around them. Kara flew through it, the hole closed behind her, and they watched as she soared into the distance.

…

"You should be right over it," Felicity said in her ear.

"Are you sure?" Kara yelled back, trying to make her voice heard over the wind as she flew through the clouds.

"Yeah, why?"

"Because there's nothing here." All she saw was the dirt and brush of the desert in every direction.

"That's not possible," Felicity insisted. "The signal's coming from those coordinates, clear as day."

"Well, I don't see anything," Kara insisted back, arcing herself downward so that she was speeding back and forth closer to the ground. "It's all just—"

 _BANG_.

Kara's body crumpled like it'd hit a solid wall before bouncing backwards in the air and plummeting to the ground. Her eyes widened in surprise as she found herself suddenly on her back, facing the sky.

"Kara? Kara, are you okay?" Alex asked, concerned.

Kara blinked several times in confusion, her limbs splayed on the ground as though she was about to make a snow angel. "I…I hit something," she said, nonplussed. Standing up, Kara's head swiveled left, right, forward, and back, but she still didn't see anything other than the plain colors of the desert. Walking forward, she tentatively raised her hands in front of her, like she was stumbling in the dark, and stopped when they flattened against something she couldn't see. "There's something here."

"What is it?" Caitlin asked.

Kara narrowed her eyes, calling on her X-ray vision, and suddenly the space in front of her was lit up with glowing bodies. Unconscious and neatly laid out, but clearly breathing, bodies.

"I found them!" Kara exclaimed, recognizing what she saw. "The Justice League! They're all here, and they're definitely alive!"

"Wait, seriously?" Felicity asked in disbelief.

"There's some kind of cloak around whatever they're in, but I can see them with my X-ray vision."

"Can you get them out?"

"One sec," Kara said. She disabled her X-ray vision and began running her hands over the seemingly solid air in front of her. She felt smooth, metallic curves but could not otherwise discern any sort of door or latch, and so finally, losing her patience, she drew back her fist and punched forward. The metal cratered underneath her superstrength in a way it hadn't against her flight collision, sending ripples through the air in a vague formation until the form of a ship materialized before her eyes, the cloak failing in the face of her assault.

The Dominator vessel was the size of a multistory house, dome-shaped, and built out of shiny grey metal they had all seen before from previous Dominator ships. The one blemish in the smooth design of the ship was a red orb that she could just barely see, way at the top of the hull, secured by three spindle-like prongs. She instantly recognized it.

"Hey, you all seeing this?"

"Oh yeah," Felicity replied. "That's the same kind of orb that controlled everyone's minds last time."

"Rather conspicuous, isn't it?" Caitlin commented.

"All that matters is that it's a clear target," Alex quipped.

"Copy that," Kara said. Crouching down, she leapt high into the air, easily clearing the top of the ship, and the peak of her jump, she pulled back her fist. The wind rushing through her hair, Kara plummeted down towards the orb, ready to disintegrate the source of all this havoc.

Unfortunately, mere feet from the orb, her body suddenly rocked off course as a glowing fist slammed into her face, sending her spiraling through the air away from the ship before landing in a cloud of dust and dirt. Shaking her head and pushing herself up to one knee, Kara looked up at the top of the ship only to catch a burst of lightning streaking down the hull. Before she knew it, the lightning stopped in front of her, yielding the sight they all feared, that she dreaded most of all.

It was Barry.

His suit was a mess, torn in various places and covered in dirt. His cowl was in pieces and fluttering around his neck, and while it hadn't been clear from the video earlier, Kara could now see that his face sported various new cuts and bruises that nevertheless looked days old. He clearly hadn't gotten through all of his Justice League abductions unscathed, but his healing powers were as functional as ever. Most disturbing to Kara were his eyes. Those same eyes, capable of so much love and affection, that she could still see light up whenever he was around a person he loved, were devoid of any emotion. The coldness in those pools made her throat tighten painfully.

She rose to her feet. "Barry," she began, holding out a hand. She was calmer than she expected, but even still there was a slight tremble in her voice. "Barry, snap out of it. Please." No reply.

"Are you sure that new suit's even helping?" Alex asked in frustration over the comms.

"She's standing, isn't she?" Harry retorted. "In any other situation, Kryptonite that close would have her on her knees." Eyes drifting over to the green glow around Barry's tattered fists, Kara had to admit that Harry had a point. She didn't feel the excruciating rivers of ice that flowed through her veins and up every nerve whenever Kryptonite affected her normally. Working her jaw, which smarted from the punch, it was clear Barry's pure speed was the biggest danger here, combining with the Kryptonite knuckles to counter her normal superstrength and invulnerability.

She tried again. "Barry, you have to fight it! We know a Dominator's controlling you!"

At first, there was again no reply, but then Barry began to grimace slightly, wincing as though a migraine was coming on. In the next moment, his forehead glowed with the pink, sparkling pattern showing a Dominator's mind control. Even worse, it was then that Barry finally spoke. "So, the puny Earthlings figured it out."

Kara took a step back, recoiling. It was Barry's voice, but there was an echo in it, similar to the way Caitlin spoke as Killer Frost. Except this echo was harsh, grinding, and undeniably alien, as though a being unfamiliar with the workings of humanoid vocal chords was gnashing through the words. The rhythm, cadence, and inflection of the speech were all wrong, a fundamental violation of Barry himself, and outrage bubbled up in Kara's chest.

"Let. Him. Go," Kara intoned darkly, fists balling at her sides.

Barry laughed, and the chilling, hollow sound made Kara's skin crawl. "Or what? Compared to me, you're practically in quicksand."

"You'd be surprised," she muttered. Hoping to catch him off guard, Kara took off, hoping to tackle Barry and physically knock sense into him. When she was inches away, however, Barry's own speed kicked in, and he grabbed her arm, spun her around at least a dozen times, and then threw her back from the ship, her velocity slamming her into the dirt.

He disappeared in a burst of lightning, and suddenly he was in front of her again as she lay on the ground. "Pathetic," Barry intoned in disgust. "You may be faster than most, but you're still no match for me."

"Stop talking like that!" Kara spat. "Don't talk like you're him. _You're not Barry_!"

"Hmm," was Barry's reply, smirking slightly as he looked condescendingly down at her. "Girl of Steel, did I hit a nerve?"

"I swear to Rao, I"ll—"

"You'll what?" Barry interrupted. "Stop the fastest man alive? You couldn't even beat a couple of humans playing mind tricks with you."

It took a beat for Kara to realize what the Dominator was talking about. "So Rainbow Raider and Psi are your allies?"

"'Allies' is rather strong a word," Barry sniffed arrogantly. "You humanoids are so susceptible to our telepathic abilities. To them, I was just another human with a lot of money who needed a job done."

"They were _mercenaries_?" Kara asked incredulously. All the grief that had been caused by those two, and the metahumans were just hired help?

"Son of a…" Felicity muttered through the comm in her ear.

"Ah, so easily deceived," Barry taunted. "I'll admit, the fear-inducing one…'Psi,' was it? She proved quite useful in incapacitating this body," he said, motioning with his hands to indicate himself. "I even let her borrow these lovely green knuckles to take you out. It really is so convenient that the ruins of your world are scattered throughout the galaxy." Barry began inspecting the bulky, reinforced Kryptonite knuckles enveloping his hands bizarrely, like he was checking on his manicure. "After that, it was a simple matter of using the orb to take over the speedster's mind."

"Just his?" Kara asked suspiciously.

"Yes well, you humanoids have proven to be astoundingly unreliable, as we all learned in our previous invasion," Barry retorted airily. "Rather than enslave a group of you and let you run amok, I decided singular control of the Scarlet Speedster would be better. And look," he gestured, waving his hands to indicate the ship behind him. "Turns out the whole Justice League can be defeated by one alien-controlled metahuman."

"And you used Barry's speed to set up jamming fields all over the country, to block our frequencies," Kara followed.

"How _do_ you humans manage without telepathy?" Barry mocked. "Some jamming transmitters, some tedious running around the country, and in no time you were…what's your expression, again? 'Chickens with your heads cut off'?"

"Well, how about you let Barry go and show yourself?" Kara asked in irritation. "You've got the rest of the League. What're you afraid of?"

Barry's chuckle was light and mocking. "You sell yourself short, Supergirl. I've great respect for your abilities, and I'll enjoy taking your life."

It was Kara's turn for a mocking laugh. "I've already seen inside your ship. All of the Leaguers are still alive. You can't kill me even if you want to, can you?" Her challenge was met with a hideous scowl on Barry's face that she desperately hoped she'd never see again, but it also confirmed her suspicions. "What's the matter? Barry fighting your mind control?" Her smug face was triumphant…and proud. "You can abuse his powers, but you can't make him kill."

Barry flexed his neck angrily as the Dominator contorted his body. "No matter. Once I take you down, your entire precious Justice League will get blasted into space far, far away. I don't have to kill you all to be rid of you and clear the way for our takeover of Earth."

"Try it." Once again trying to catch Barry off guard, she stood suddenly and used her superbreath, hoping to blast him into the air where he'd be more vulnerable, but once again Barry was simply too fast. The air was barely out of her lungs before he sped across her, slamming another punch into her stomach. She stumbled but recovered, only for Barry to zoom past in the other direction, clocking her in the face. Desperately she tried to raise her arms to defend herself, but she couldn't stop the predictable left-right-left-right assault simply because of how blindingly fast he was. Like Clark before her, her own enhanced speed only gave her enough forewarning to know a strike was coming, but her reflexes to do anything about it simply weren't good enough. Finally, a jarring right hook sent her back to the ground. She spat dirt out of her mouth as she pushed herself onto her knees.

"Interesting," Barry observed, dropping out of superspeed to casually pace in front of her while examining the green glowing from his fists again. "You don't seem as affected by the Kryptonite as your cousin. The new suit, perhaps?"

Kara wasn't keen on this Dominator figuring out her only protection from the deadly ore, so she leapt into flight in order to get some distance from him. Before clearing more than a few feet, however, she saw a streak of lightning and then felt a sharp tug on her cape, the sheer force of the pull dragging her off course. Then she was swinging around and around through the air, the newly designed cape unfortunately working against her as this one wrapped around her neck before flowing down her back. Pressure built around her throat as Barry spun her in circle after circle, until suddenly the pain vanished and she hurtled through the air, stopped only by a stack of boulders hundreds of meters away that her body pulverized. Dust and dirt choked her as she held her throat and dry-retched from the strain.

Before she could catch her breath, a hand grabbed her bodily and speeded her all the way back the way she had come, throwing her into the dirt at the foot of the huge prison ship. As she rolled to a stop, Kara didn't have to look up to know Barry was stalking towards her again, relentless in his toying of her.

She closed her eyes as she heaved and coughed, always knowing it would come to this but still nervous nevertheless. "He's too fast," Kara muttered. "I can't even get airborne. I can't do anything without him reacting immediately."

"Kara…," Alex warned over the communicator.

"I have to do this, Alex."

A moment of silence passed before Alex replied. "Be careful, Supergirl."

Taking a deep breath, Kara got back up on one knee and rested her right hand on her left upper arm, as though it was injured. The Dominator contorted Barry's face into a sneer as he approached, pink sparkling energy on his forehead glowing, if possible, an even more sinister shade. "Ready to give up, Supergirl? I'll put you next to your cousin, if you'd like. The last children of Krypton can wander the void of space together, with dead human bodies as company."

"Remind me to tell Barry never to do a bad guy speech," Kara grunted. "It doesn't suit him." With that, she raised her hand from her upper arm to her shoulder, pressing her fingertips against the pad. Nothing happened outwardly, but she felt a stab as the hidden Kryptonite needle pierced her skin, injecting her with the V-9. She winced again a couple seconds later when the needle retracted from her body back into its lead casing.

Barry's eyes narrowed. "What are you doing?"

"Leveling the playing field," Kara growled. Looking down, she glimpsed tendrils of lightning curling around her hands and forearms. A slight tremor through her body quickly morphed into violent jerks and convulsions, like she was being electrocuted. Quite the opposite of Kryptonite exposure, Kara felt like every artery, vein, and nerve was on fire as all her muscles seized up, and against her will her head jerked back, her eyes burning as she involuntarily let out an anguished scream towards the sky.

"What've you done?" Barry demanded, the Dominator's control surrendering a look of alarm.

"Kara, talk to me!" Alex cried.

As suddenly as the agony had come on, it stopped, and Kara choked out air her body had been unable to release. Tipping sideways, she threw out a hand to lean against the side of the Dominator ship, breathing heavily, and turning her head, she saw herself in the reflective hull. Despite the metallic material and awkward curve of the ship's exterior, Kara could still make out her own eyes, charged with an energy quite different than her heat vision. If anything, it looked like miniature lightning bolts were shooting across her blue irises.

"No," Barry snarled, rushing forward to grab her. Without even thinking, Kara raised her hand and caught Barry's wrist, bringing him to a dead stop. It took both of them a beat to realize what had happened: Barry used his superspeed, and Kara _stopped_ him.

"Barry," Kara said, resolve flooding her body along with the V-9, "I'm bringing you home."

…

 _Author's notes: Kara's new suit is based on artwork and promotional images for Supergirl in the Injustice 2 video game._


	4. Chapter 4

One hand around Barry's wrist, Kara snatched the collar of his suit with the other hand and bodily slammed him against the ship's hull, using just enough strength to lift his feet off the ground.

 _Crush him._

"Let Barry go," Kara commanded, her eyes locked on the pink swirl of energy on Barry's forehead.

"You first," Barry snarled, and suddenly his body became a blur, his molecules vibrating as he dropped through her hands and ran off. In a blink, Barry was speeding back towards her, his fist pulled back, but Kara had V-9 coursing through her veins and could react to it now, sidestepping away while simultaneously using an open palm to block and redirect the strike. She tried to grab Barry's suit again to pin him down, but he twisted away as he ran past and stopped a safe distance from her, turning around in anger and frank astonishment. "How?!"

"Wouldn't you like to know?" Kara taunted, wanting to keep Barry off balance. The V-9 heightened her speed and reflexes, giving her the ability to keep pace with Barry, but defeating him was never the goal. She needed the speed to give her a window to destroy the orb on the ship that was controlling his mind.

Crouching down, she launched into the sky, shooting up so fast that Barry's desperate lunge for her cape left him clutching air. Hoping to finally put an end to everything, Kara snapped her head sideways as she became level with the top of the ship and fired her heat vision at the orb, scoring a direct hit.

Unfortunately, the orb was unscathed.

"It looks like the orb's made of some kind of heat-ablative material," Caitlin noted over comms. "You'll have to take it out the old-fashioned way."

"Of course," Kara muttered sarcastically. "Can't make it too easy." Aligning her body parallel to the ground, she sped towards the orb, intending to ram through it, but she got violently knocked off course by a sudden wind funnel. Barry had used his arms and superspeed to blow her off her trajectory, and she ended up zooming past the orb, out of arm's reach.

She tried again with another pass, but Barry then ran up the side of the ship and shoved her away. She tried a third time, and a fourth time, on and on, but again and again Barry was able to block or divert her. Her newfound speed meant that he could no longer throw her around, attack her indiscriminately, or otherwise catch her by surprise, but the fact that Kara's target was so obvious meant that he had the advantage in predicting and frustrating her, and Kara was determined to exhaust every possible alternative before even considering attacking Barry directly.

 _Destroy him._

Kara grunted in annoyance as her latest pass ended in Barry vibrating through her swinging fist and then blowing her off course yet again. "I can't get a shot at the orb," she said into her earpiece. "Barry's still too fast."

"I thought the V-9 made Trajectory faster than Barry," Felicity said.

"At the time, yes," Caitlin clarified, "but that was years ago. His connection to the Speed Force is so much stronger now. Honestly, I'm surprised Kara's kept up as much as she has."

Barry had now taken up a running defensive pattern up, over, and around the ship to block her no matter which angle she took. Hovering in the sky as she watched his trail of lightning swirling around her target, Kara shook her head. "I can't get past him. However the Dominator's controlling him, he's just too fast."

"Don't try to beat him at his strength, Kara," Alex suggested. "Beat him with yours."

Stuck as Kara was in a repetitive loop with Barry's counterattacks, Alex's comment made sense. With the V-9, Kara had been trying to outrace the fastest man alive, when maybe the key to all this was in her own abilities. This gave her an idea.

Adjusting her body in midair, Kara made a beeline for Barry, making a show of intending to simply punch him into oblivion from above and timing it to catch him on the ground rather than on the ship's hull. Of course, Barry dodged, and Kara pounded her fist into the dirt instead. Straightening up, she saw Barry halt a safe distance away from her, observing with a bemused smirk.

"Big mistake coming back down from the sky, Supergirl," he taunted. "I'll make sure you don't fly again."

"Don't count on it," Kara shot back. Rushing forward, she aimed another punch at Barry, who again vibrated himself so that she passed right through. She expected the move, and instead of turning around immediately to defend against a counter, she used the momentum to continue running at a flat out sprint away from the ship. Barry, caught off guard that she was heading _away_ rather than _towards_ the orb, quickly recovered and gave chase.

Not wanting to stray too far from her objective, Kara soon course-corrected and began veering back towards the ship. Vaguely, she hoped the split-second lead she had on Barry would be enough, but she already detected him accelerating, angling to cut her off, which forced her back. Soon, she was running in literal circles around the Dominator prison, and Barry matched her stride for stride, taking an inside track so as to constantly be between her and the orb.

Around and around they went, Kara's legs straining and her lungs burning as she sought a way past the Scarlet Speedster. A feeling of déjà vu squeezed her heart as she ran side by side with Barry, recalling the times they had raced in the past. They'd done it playfully, when they were still friends before becoming more to each other, to see which hero was truly faster. Oliver called it a frivolous waste of time better spent training. J'onn thought it was unprofessional. For the two of them, though, it was a representation of who they were. Yes, they wielded extraordinary powers, and it was their responsibility to use these powers to help others, but they were not ashamed that having abilities could be _fun_. It was simple expressions such as these over which Kara and Barry had forged their connection, and as she raced him now, Kara was determined to get him back any way she could.

It was now or never.

Kara's feet tripped over themselves, unused and exhausted as they were to this kind of speed. Her legs left the ground as she threw her arms out wide in a vain attempt to regain her balance, even as she tilted sideways and her chest turned towards Barry. In a blink, he took the opening and sped forward to finish her.

 _Kill him._

The V-9 putting her reflexes and perception on equal footing with Barry's, everything seemed to happen in slow motion. As her hair and cape flipped behind her, she saw the Dominator distort Barry's face into a look of triumphant hunger. She saw his legs churn underneath his body. She saw a green glowing fist cock back to knock her out.

And she got him.

When he was just beyond arm's reach, Kara slammed her hands together with all the weight of her superstrength, producing a thunderclap so powerful that a concussive wave blasted from between her fingertips, knocking Barry into the air. Her own body still airborne from her "trip," Kara immediately transitioned into flight, taking advantage of the precious moments when Barry was distracted and off his feet. Calling on every bit of speed the V-9 bestowed upon her, Kara raced to the ship and blasted right through the orb on the Dominator's ship, disintegrating it before Barry hit the ground.

Even from the top of the gigantic Dominator prison, Kara didn't need her superhearing to register Barry's anguished scream. Flying back around in panic, Kara landed next to him only to find him convulsing in the dirt not far from the ship, eyes shut tight. She fell to her knees and grabbed his face in her hands. "Barry! Barry!"

He continued to thrash for another few seconds, and Kara was about to yell at Caitlin to tell her what to do, when Barry suddenly stiffened, his back arching unnaturally. The Dominator pattern on his forehead sparked and blinked a couple times, and then slowly faded away, leaving behind normal-looking human skin. His body sagged lifelessly as it did so, and then it stopped moving entirely.

"No," Kara gasped, desperately stroking his face with her hands, "no, no, no." She leaned down to listen to his chest, but she was so out of breath from her run that she couldn't focus her hearing over the sound of her heaving lungs and pounding heart. "Barry? Barry please," she begged, looking at his lifeless face as tears started to form. "Wake up." Had she made a mistake? Did destroying the orb somehow cut off Barry's life? Did she…was she responsible for…?

After what felt like an eternity, Barry's eyes opened slowly, and Kara's heart leapt into her throat. His head turned a fraction to the side between her hands, and though his eyes remained unfocused, he still seemed to know her. "K—Kara?"

"Yes!" Kara choked out, relieved beyond measure as she nodded desperately. "Yeah, it's me, Barry! It's Kara, it's your Kara." Upon hearing her voice, Barry's face lit up a little, giving a small smile. His eyes then promptly rolled up into his head, and he lost consciousness. However, the fact that he had spoken and at least shown life briefly galvanized her into action, and she wiped her eyes before shifting herself to take Barry into her arms and get him to Caitlin as soon as possible.

"Hang on, Barry. If you die, I will _so_ kill you." She stood up, Barry in her arms, and prepared to take off, but her legs suddenly wobbled and she fell back down into the dirt. A wave of exhaustion and weakness overcame her that had nothing to do with Barry's weight or her run, and her sudden loss of strength surprised her so much she was temporarily speechless.

 _You're soft._

"Kara, the V-9's wearing off," Caitlin warned.

"I…my muscles are all…" Kara started, barely able to explain the pins and needles stabbing her all over her body. Pain was also starting to build in her head behind her temples.

"Kara, get back to S.T.A.R. Labs now!" Alex commanded. "We have no idea what the side effects are going to be!"

"I'm not leaving Barry here!"

"You're not leaving at all," growled an alien voice. Kara barely got her head around before she saw an alien appendage swinging towards her face. The fading V-9 had made her weaker and even slower than normal, and her head rocked sideways as the Dominator's attack knocked her clear of Barry's prone form.

Her body rolling and her head swimming, she looked up to see a Dominator bearing down on her. Behind it, Kara could make out a hatch that had opened up in the hull of the ship, revealing a small compartment that she belatedly realized was encased in lead. The alien controlling Barry had been there the whole time, and as it stalked towards her, it ripped one of the Kryptonite knuckles from Barry's hand and smashed it on the ground, producing a razor-sharp, glowing shard that it flipped with disturbing ease between its fingers.

"Die, Kryptonian," the Dominator intoned, the alien hiss registering in her head. The V-9 had worn off, Barry was completely knocked out, and she was suddenly so exhausted that her body wasn't reacting fast enough to her mind, which was itself ringing with pain. Almost detachedly, she watched as the Dominator raised the shard, the combination of Kryptonite and its alien strength surely enough to pierce her chest.

 _You're weak._

Luckily, it never fell, as the point of a knife blade suddenly protruded from the Dominator's neck. The desiccated alien jerked once, its eyes widening as it seemed to realize for one moment what had happened, and then its body went limp. The knife point retracted, and the alien body collapsed in a heap, revealing a white, disheveled figure behind it with a hidden blade sticking out of her sleeve.

Kara's eyes went wide with shock and relief. "Sara?"

The White Canary immediately fell to her knees, having expended what little energy she had. Her suit was torn, her blond hair was a mess, and her head sagged, but she was an indescribably welcome sight to the Girl of Steel. "Kara?" she choked out, confused and discombobulated. "What's going on? I just…," she trailed off, seeming to lose her breath as she gestured incoherently at the ship behind them, "…I just fell out of some porthole on the other side of that thing and heard noises. Is that a Dominator?" she finished in the same breath, seeming to just realize what she had done.

Kara said nothing, fairly sure "it's a long story" was not going to be satisfactory. Somehow, the destruction of the orb and the Dominator's attack on her had caused the ship to release whatever hold it had on its Justice League prisoners. Sara had clearly been through the ringer, probably overwhelmed so fast by Barry's kidnapping that she had no clue what had happened, but generally she seemed okay, which Kara was grateful for as she herself desperately needed help.

 _Surrender._

The high-pitched whine in her head continued to build, and thoughts she had dismissed as just random strands infiltrating her consciousness during the heat of battle were now an insistent voice that was slowly overtaking her. The V-9 had awakened something inside of her that was threatening to consume her mind, and she wasn't sure how much longer she could maintain her self-control. If she was going to save Barry, and frankly herself, she needed to leave immediately.

Tearing out the communicator from her ear, she tossed it to Sara, who bobbled it before getting a grip on it. "Someone will talk you through how to help the others," she said briefly, indicating the ship with her eyes. "Do what you can."

"Wha—wait, where are you going?" Sara stammered, still breathing heavily from her ordeal.

Kara didn't answer as her vision tunneled and her senses became dull. Her singular focus now became getting Barry help. Commanding her body to listen to her this time, she lifted him in her arms with an enormous effort, her breathing labored and her muscles shaking. With more willpower than she ever thought she possessed, she soared into flight, straining desperately to reach S.T.A.R. Labs and save them both.

 _You're too late._

…

Barry hoped it had all been a nightmare. Waking up to realize it wasn't was one of the worst experiences of his life.

He remembered it all. Psi had been able to surprise him and paralyze him with fear during the mob scene in Central City, and by the time he realized the unassuming human next to her was actually a Dominator messing with his senses, he couldn't defend himself as he fell under its control.

He saw, heard, and felt everything as the Dominator manipulated his body. In horror, he'd watched as the alien equipped his fists with glowing green knuckles it had gotten from who-knows-where. He'd screamed in silence as those fists took down Oliver, took down J'onn, took down Clark, took down Wally. He'd fought in vain as the alien placed transmitter after transmitter in his hands and forced him to plant them in various hidden locations around the country, knocking out the JL communication frequency in every area where Leaguers were active.

He laid hands on Kara. Attacked her. Rammed his fists into her over and over again. His mind had begged and pleaded for his body to stop, but the Dominator's control over him was too strong. His consciousness was left to watch as the woman for whom he would gladly give his life struggled against his relentless assault.

He'd tried to resist. Oh, he'd tried. Against the Dominator, he'd pushed the fullest reach of his will to try to take control. He'd been successful to a point, stopping the Dominator from using his body to kill the first Leaguer he went after. Oliver had never seen it coming, and the alien was about to push his vibrating fist through the unconscious archer's chest, but Barry's consciousness had rebelled so violently, fighting for mastery, that the Dominator settled for incapacitation. After that, the alien simply found it took less energy to knock out and kidnap rather than kill, lest Barry's mind revolt again.

To an extent, the same effort is what kept him from vibrating at just the right frequency to chew up Kara's insides. It kept him from trying for a fatal strike, but that was all he could manage. The punches he threw, and the blows he inflicted, he just couldn't stop, and it made him sick. It made him a monster.

"How is she?" were the first words out of his mouth upon waking up.

Caitlin sighed, seeming to expect the question. She looked down at him in concern as he lay on one of the beds in S.T.A.R. Labs. "You really should focus on your own rest."

"Caitlin," Barry repeated, desperation in his eyes. "How is she?"

She hesitated a moment before responding. "She's unconscious. She barely made it to our front door before she collapsed."

"Will she be okay?"

"Barry…"

" _Will she be okay?_ "

"I don't know," Caitlin said, shaking her head. "It's really up to her now."

"What? What does that mean?" Barry asked, shaking his head in confusion.

"She took V-9," said a voice from the doorway. Barry turned his head and saw Alex observing him, leaning against the frame with her arms crossed.

"She took _what_?" Barry demanded, shooting upward into a sitting position. His head swam painfully, but the sudden clench in his chest at hearing that bit of news overrode it.

"Hey, you shouldn't be sitting up!" Caitlin exclaimed, trying to push him back down.

"That's how she got faster," Barry muttered, ignoring Caitlin's attempts to calm him. "How could you let her do that?!" he demanded, looking at the two women.

"She needed to save you," Alex said, coolly. Barry couldn't tell if he was imagining an accusatory tone in her voice.

"She felt it was her responsibility as one of the founders of the League," Caitlin added. "She needed a way to get past you to save everyone, and V-9 was her best shot."

Barry buried his face in his hands. He couldn't truly be angry with Caitlin, or Alex, or anyone else really, when he knew where the blame lay. He was responsible for downing the League's communication system. He was responsible for the League's capture. He was responsible for Kara's condition. "I attacked her. It's all my fault…"

"Kara wouldn't want you thinking that way."

He looked up. Alex was still regarding him from a distance. It was abundantly clear he was not her favorite person right now, but in his experience, she'd always had a good sense of Kara's feelings, and she seemed to be prioritizing them now. "It won't help her now for you to wallow in your own self pity, and if you honestly think the Girl of Steel couldn't handle a few really fast punches, you're not giving her enough credit."

"I…I'm not…," he began, but the words died in his throat. Girl of Steel Kara might be, but it was Alex who was currently holding it together with superhuman resolve, and above all else, she was reminding him that the person they both loved needed their support now. Everything else could wait. He swallowed and tried again. "How's her condition?"

"Her body is rejecting the V-9 and trying to flush it out of her system," Caitlin answered. "I've done all I can, but like I said before, it's really up to Kara and her biology now. My best guess is that if she makes it through the night, she'll be out of the woods."

"What time is it now?"

"Quarter past eight. The sun just went down."

Barry took a breath. Kara had been there for him, and now he needed to be there for her. Swinging his legs off the bed, ignoring both his nausea and Caitlin's protestations, he got unsteadily to his feet. "Where is she?"

"This way," Alex replied, tilting her head before leaving the room. Stumbling along, Barry followed.

…

 _That cloud looks like a puppy._

She had no idea where she was, or how she'd gotten there, but at the moment, upon opening her eyes, Kara was content to lie on her back and stare at the blue sky above her, small white clouds passing by. It took her a few more seconds to realize how weird that was.

She sat up. The last thing she remembered was the alarmingly accelerating pavement in front of S.T.A.R. Labs rushing up to meet her and the last second adjustment she'd made so that Barry would land on her rather than the other way around as they crashed from the sky. Swiveling her head, she realized she was lying on a street, surrounded by the normal shops, restaurants, and apartment complexes one would associate with your typical big city, with the glaring exception that the streets were deadly silent, without another soul in sight. She saw the Catco Worldwide Media insignia on a particularly tall skyscraper a few blocks away.

 _This is National City._

How did she get to National City? It was nowhere near S. . Labs. She clambered to her feet, her cape flowing in a familiar way down her back, which gave her another surprise. Looking down, she realized she was back in her classic suit, rather than the battle-ready outfit she'd flown out in to save the League. When did that happen?

"What is going on?" she muttered out loud.

"For someone who's faster than a speeding bullet, you are _incredibly_ slow."

Turning slowly, Kara tilted her head up to regard the floating figure. Skintight black combat suit covering her from neck to feet. A small, plain, red S-shield on the right side of her chest. Blonde hair billowing in the light breeze. Same lips, but the smile was colder. Same eyes, but her glance was harder.

"You," Kara said, simply. She should have been shocked, but the voice in her head as she'd tried to save Barry suddenly made so much sense.

"Me," her opponent agreed, lightly drifting to the ground to face her. "Or you, actually. Whichever you prefer. This is happening inside your head, after all."

Kara looked around, mildly surprised that the inside of her mind structured itself like her home city, before facing her…whatever she was. "So is this a side effect of the V-9? Making me relive my worst nightmares, splitting my personality, like when I was on red K?"

Her double, the person she had been when that artificial poison had clouded her mind and tainted her senses, laughed in her face, a cruel chuckle as though making fun of someone slow. "Red K…V-9...why are you so convinced that this," she inquired, sweeping her hands up and down to indicate her own body, "only exists when you get drugged somehow?"

"Because that's the truth," Kara spat.

"No, silly girl," her double crooned. "Don't you see? All of these adventures you've had only prove my point. It doesn't matter if you get poisoned with red K. It doesn't matter if some metahumans get to you. It doesn't matter if you shoot up some speedster drug." She took a few steps forward. "Every single time, the effect is the same. You become me."

"No," Kara shook her head furiously, fighting the urge to back away from her double. "I didn't become you after taking V-9."

"Darling, what do you think is happening now?" her double asked, taking a few more steps as she spread her arms out. "When your body wakes up, it'll be me that's in control. You've already heard my voice in your head, and…well, you and I are the same, aren't we?" she teased, playfully pointing at her identical face.

"We're not!" Kara yelled, unable to keep the words from getting under her skin.

"Oh Kara, so determined to ignore the truth," the double continued, shaking her head as she stalked even closer. "I'm not a side-effect. I'm not something foreign. You just can't see that _I'm_ who you really are, who you were always meant to become. You're fighting it, but it's only a matter of time." She walked right up to Kara's face, and Kara, completely out of sorts as to what this dream or hallucination or mind palace scenario would do, was frozen.

"Time to stop fighting. It's my turn," her double whispered, and for the briefest moment, as she stared into her own face, Kara saw her blue eyes glow a deadly red. She couldn't decide if it reminded her more of red Kryptonite or the Velocity 9 serum.

…

"She's stable for now, but her vitals are critical."

Alex wasn't sure Barry was really listening as they walked into S.T.A.R. Labs' intensive care room, where Kara lay on a medical bed surrounded by machines and dressed in a plain medical gown. She and Caitlin had peeled the battle suit off her shortly after her return as they fought to get her vitals under control. Barry simply pulled up a chair, not even thinking about his own tattered suit that he was still wearing, and sat down by her side, still not saying a word.

Even knowing the circumstances of this whole mess, Alex's emotions burned at the memory of watching Barry sink punch after punch into Kara's body. Supergirl or not, Alex would never stop wanting to protect Kara from harm, and she would have raced out to throttle Barry herself if she could have. However, standing here now, seeing the total devastation in Barry's eyes as he silently kept watch over her sister's still form, his mouth covered by his clasped hands, she knew without a doubt that the man out there guarding the Dominator ship had decidedly _not_ been Barry Allen. She had never seen a person look at her sister with so much love, and so much heartache, as he did right now.

Sadly, she turned her eyes on Kara's motionless form. She wished she could jump into her mind, like when the Black Mercy had attacked her, and reach out to bring her back to the people whose lives would never be the same without her. Unfortunately, though, this time Kara would have to fight this on her own, and there was absolutely nothing she could do to help.

 _Watch it, Danvers_ , she caught herself. _Take your own advice. No self-pity_.

Caitlin had retired to an empty office elsewhere in the lab. At Alex's and Barry's insistence, Felicity and Harry had left to get some rest, Felicity staying with Iris and Harry muttering something about breaking into Cisco's empty apartment. It was just the three of them now, so Alex pulled up a chair next to Kara's bed, on the opposite side from Barry, and sat down. The two briefly made eye contact, coming to a silent understanding, and then settled in for their night-long vigil.

…

Before she could blink, Red Kara had her neck in a vice grip.

 _This is all in my head! Why does this feel so real?_

Kara felt her body hurled with Kryptonian strength through a nearby office building. Paper, swivel chairs, and cheap fluorescent lights flew by her as she smashed clean through the opposite wall and onto the next parallel street. She had barely climbed back to her feet when Red Kara was on her again. She blocked the first couple strikes, but her opponent seemed to have an innate sense of her moves, and soon Kara found herself in a headlock.

"You're just in my head! This isn't happening!"

Red Kara clicked her tongue in disapproval, like she was lecturing a stubborn child. "Kara, of course this is in your head, but why would that mean it isn't real?"

Kara opened her mouth to respond but then immediately closed it, frowning as she wondered idly if her evil twin knew she'd just made a Harry Potter reference in the middle of trying to kill her, but given her current and very real feelings of choking, she supposed the essence of the comment was appropriate. Shifting her weight, she fought out of the hold, but another quick strike sent her back onto the pavement. She quickly pushed herself up to a knee, prepared to react to another assault, but her attacker hadn't pressed her advantage, instead regarding her contemptuously with her arms crossed.

"Can't understand why I'm beating you?" Red Kara taunted. "You think our moves should be identical?"

Kara seethed at how her opposite was guessing all her thoughts.

"I know you, Kara Danvers," her double continued, emphasizing her last name with mock air quotes. "You and the humans. You fight for them. You try to fit in with them. You _love_ them," she said, wrinkling her nose in disgust. "I've tried to get you to forget all of that, claim your true calling as Kara Zor-El, but you're so stubborn."

"What are you talking about?" Kara asked, narrowing her eyes suspiciously.

"Come on, Kara, don't act like you don't remember."

 _My nightmare, before my panic attack_ , Kara thought bitterly. She said nothing, but again, her twin guessed at her thoughts.

"The dream was a little on the nose, I'll admit, but your mind was vulnerable after those metahuman attacks." Lazily, Red Kara began ticking off her fingers. "Your duty. Your family. Your love. You'd be so much better, so much stronger, if you left that all behind. If you let them all die."

The broken bodies from her dream pushed their way into her mind's eye. She shook her head. "You're lying. You want me to believe you caused that dream?" Kara tried to give off a brave laugh. "That was just Rainbow Raider and Psi messing with my head. You just want me to think you're more powerful than you are."

Red Kara shrugged in response. "Have it your way, then. You know the bottom line. You know I'm only telling you the truth."

"What you want isn't leaving everything behind. It's burning everything to the ground," Kara retorted angrily.

"Same difference," Red Kara replied airily. "All I've done is try to get you to follow a better way, your rightful way, because I know what you are, and what you can be."

"Is there a point somewhere in this monologue?"

Red Kara rolled her eyes, still taking on the attitude of a frustrated teacher. "My _point_ , Kara, is that you, on the other hand, don't know me. You can't fathom me or what I can do or what I represent in you." A rush of air, and Red Kara was in front of her, a fistful of her suit in her left hand. Once again, Kara was just a breath too slow to react.

"You can't see that I'm _better_ than you."

Kara made a move to break the hold, but Red Kara quickly smashed her forehead into Kara's face. A subsequent knee into her gut forced the air from her lungs, and once again she was forcibly thrown into another building, cratering the concrete wall before collapsing forward onto the pavement. Pushing herself up painfully, she noticed a bright red smear on the ground beneath her. Gingerly, her hand shaking slightly, she touched her fingers to her mouth, felt the shock when she saw the blood on them.

Looking up, she watched her double smirk triumphantly. Sickeningly, in that instance, Kara truly could see into the mind of her alter ego, and she knew that Red Kara was gleeful at having drawn blood. It was arguably the most visual sign of weakness a Kryptonian could show on this planet. In Red Kara's mind, it just confirmed everything she'd been claiming.

 _Is she right?_

Kara hadn't landed a single hit. She was faced with herself and yet she was second-guessing everything. She was already bleeding. What if she couldn't win? What if anger, and power, and hatred, really were stronger? She'd already admitted it to Alex after her panic attack. Those feelings inside her didn't come from nowhere, and for someone like her, those feelings were _dangerous_.

Wobbling as she struggled to her feet, Kara staggered forward a few steps with her arms held up weakly to defend herself, and looking across from her, she couldn't help but see strength. Resolve. Full ownership. Red Kara knew who she was and how she felt. She didn't have to question the impulses that ran through her mind. She embraced them. Kara had tried her whole life to live up, not just to her cousin's example, but to the example she held for herself, as someone who'd use her gifts to accomplish as much good in the world as she could. How could she do that when the instincts that produced the doppelgänger in front of her lived in some dark corner of her subconscious? What if it wasn't as simple as just avoiding red K or V-9?

Red Kara grew, if possible, even more smug as she sauntered towards her. "You see? You can't stop me." Cracking her knuckles, she strode to within arm's reach. "It's time to reach our full potential." She pulled back her arm. "Unfortunately, that doesn't include you." Her fist flew forward.

…

As the night wore on, Alex and Barry settled into an unspoken routine. At least one of them was with Kara at all times whenever the other one needed to use the bathroom or get more coffee for the both of them. Neither of them got up at the same time, as if the motion and noise of two people around Kara was simply unacceptable. Most small changes in Kara's vitals Alex had enough expertise to interpret, but if she was ever less than absolutely certain, Barry would speed out to ask Caitlin, who was also barely sleeping anyway.

It was Barry's turn to be restless, and he alternated between pacing just outside the doorway and leaning against the arch while maintaining his worried vigil, leaving Alex sitting next to Kara's bed. They'd observed odd changes in Kara's brain activity as the hours passed, but unless and until something drastic happened, they could do nothing but watch and wait. Alex's hands were both wrapped around one of her sister's, and she spoke softly to it, not wanting to disturb her and yet desperately wishing she'd wake up.

"You always tossed and turned in your sleep, when you first came to live with us," Alex said, remembering the days when the two of them shared a room, at first by parental command, and later by choice. "I thought it was annoying. I wanted any reason to find something else wrong with you. But I also knew you were still grieving what you'd lost, and it made me feel guilty for…for wanting my life to go back to the way it was."

She lifted her eyes dejectedly to look at Kara now, so still and peaceful on the medical bed, the electrodes stuck onto her forehead notwithstanding. "Kara, I know sometimes you feel like you need to justify yourself being here. You're afraid that people will start to fear you, and that if you slip up, we'll abandon you." Her fingers momentarily gripped the hand between them more tightly. "I just…I just want you to know that I'll _never_ abandon you. You're not perfect, you're not infallible, and I wouldn't have it any other way. You're my sister, and you're my family. "

Alex blinked and sniffed a couple times, determined not to shed tears, not now. "You make me stronger, Kara," she finished. Looking up and around, she saw Barry leaning against the doorway, able to hear every word, but she found it hurt to look into his face, since it reflected the same constant thought she was having. They both just wanted her back.

…

 _You make me stronger, Kara._

 _Alex_? Kara thought. Without even processing her own intent, she deflected Red Kara's incoming punch and took control of her arm, swinging her body around so that her back faced Red Kara's front. Jamming her hips backward, Kara tightened her grip on her opponent's arm and forcibly flipped her over her shoulder, slamming Red Kara into the pavement so violently that the ground cracked beneath her.

Dropping the arm in surprise, Kara immediately jumped back into a defensive posture, preparing for a counterattack, but her double seemed just as shocked as she was. It took another few seconds for Kara to realize her thoughts had drifted to Alex, and she had just channeled one of her sister's favorite fighting techniques, the same one they'd just started working on.

Red Kara scrambled to her feet, her face impossible to describe with any other word than "pissed." She glared fiercely. "How did you do that?"

Kara's smile became easy as her confidence began to grow. "Looks like there're things about me you can't figure out either."

Growling, Red Kara sped forward, going after Kara with a flurry of punches, but Kara handily blocked and countered every strike. She had no idea how long this fight had been happening, either in her mind or in real time, but it was only now that she started feeling in control, like realizing she was in a dream while she was still dreaming. She had never pulled off Alex's throw before, but now she could feel herself dictating the terms of this whole mental experience, willing herself to channel all of Alex's fighting expertise.

Clearly getting angry, Red Kara charged forward, trying to knock Kara off balance, but Kara took advantage of her overreach, dodging and slamming her elbow in her opponent's face. Staggering back, Red Kara touched her hand to her nose, seeing blood when she pulled her fingers back. Kara cocked her eyebrow. "Now we're even," she taunted.

At this point, her double abandoned all pretense of making their grudge match slow and personal. Releasing a guttural scream of rage, Red Kara took to the sky and immediately shot at Kara with her heat vision. Kara dodged and went airborne as well, only to have to dodge again to avoid a blast of freeze breath. She flew in to counterattack but had to switch to defense as Red Kara put on a burst of superspeed to try to catch her off guard and regain the upper hand.

On and on they went, the both of them emptying their repertoire of Kryptonian superpowers when they weren't pummeling each other hand-to-hand. Charred lines of destruction raced around Kara's mental recreation of National City as streams of heat vision shot back and forth. Windows blasted out and buildings collapsed as superbreath and superstrength sent both Girls of Steel plunging through the concrete structures. At one point, Kara got blasted by her own trick, as her twin slammed her palms together right in front of her, the concussive wave sending her into the pavement. When she shook her head and looked up, Red Kara was already flying towards her, a car held up above her head.

She ached all over her body from their endless brawling, her suit torn in several places, one eye bruised and rapidly swelling, and blood from her forehead matting her hair. Red Kara didn't look any better, but the pure rage in her face gave her a manic quality, as though she was playing a game of endurance chicken that she absolutely refused to lose. Even if Kara had willed this mental version of herself to even the odds, she was starting to worry that her evil twin would simply outlast her.

 _I have to end this._

…

Hours had passed, and now it was Alex's turn to stand restlessly. She leaned against a counter, arms crossed and eyes staring at the floor. Barry couldn't blame her. As much as they wanted to keep constant watch over Kara, it was just so hard to look at her in this state. For maybe the hundredth time, as he sat next to her shoulder, he reached out and gently stroked her hair above her forehead, ostensibly to brush away a loose strand, but that excuse had stopped holding water after the third or fourth time. He really just kept hoping she'd respond to his touch, the way she would when they woke up together in the mornings.

Privately, he continued to wrestle with his guilt over the part he'd played in getting Kara into this state. He knew Alex was right that Kara wouldn't want him blaming himself, and he knew the thoughts did nothing useful for her now, but he couldn't stop dwelling over his role in incapacitating the League and forcing her to extremes. However, at the same time, he also couldn't help feeling, if possible, even more impressed and proud by Kara's pure strength and bravery. She had taken a speed drug with an extremely dubious history of past users, and instead of being ruled by its effects, she had effectively harnessed its power to do what she had to do. All on her own, she'd saved the League, and him as well.

Well, perhaps not on her own. Barry knew she'd be the first to credit Alex, Caitlin, Felicity, and Harry for helping her accomplish something of such a scale. That's probably what made her so special and occasionally so infuriating, and what made him love her so deeply. She always put the highest value on others, never hesitating to take on more than her fair share of the burden.

He exhaled in frustration, bowing his head and grabbing fistfuls of his own hair with both hands. "This is all so messed up," he muttered. "I wish I hadn't been so _stupid_ , letting myself get taken down by that psychic meta. I wish someone else had been able to stop me first." He looked back up at her, lying on the medical cot. "I wish you hadn't used V-9."

He sniffed a couple times to maintain his composure. "It was reckless," he scolded angrily, building up steam. "It was risky. It was impulsive. It could cost you your life." Taking another breath, he then shook his head sadly as he got up from the chair to lean against her bed, softly cupping her cheek in one hand. "And it was the bravest thing I think I've ever seen anyone do."

Of course, she didn't respond. His thumb traced small circles on her cheek as she continued to lay there, her hair fanning out around her face, looking for all the world as though she was simply asleep. "As the Flash, I know I have to set an example, to inspire people to be the best versions of themselves." He leaned a little closer, shifting his hand to the top of her head. "But as Barry, as _your_ Barry," he continued, softly, "I'm inspired by you every day, Kara Danvers. You make me a better hero." Closing his eyes, he gently placed a kiss on her forehead before leaning back, resuming his seat in his chair.

He felt Alex looking at him, so he glanced up, but the residual hardness she, either consciously or not, had been directing at him throughout the night had dissipated. There was no question that they were hoping for the same thing.

…

 _You make me a better hero._

 _Barry_ , Kara smiled, without even fully knowing why. Red Kara had just begun the motion of hurling the car she was carrying over her head, but everything to Kara had started to slow down. She felt a warm tingle throughout her body, a far more pure feeling than what the V-9 had induced, and she suddenly understood.

She got her feet underneath her and pushed off towards the sky, blasting into flight. Lightning trailed in her wake as she went straight at her double, the car still barely on its way towards her as she slammed into Red Kara far faster than either of them expected. Adjusting, Kara turned over and hurled Red Kara towards the ground, only to speed past her and land one final horizontal shot, ensuring that her twin's limp form crashed through a couple buildings before crumbling to the pavement.

Sensing the end of the fight was near, Kara flew over and landed next to her opponent, fists on her hips. Breathing heavily, groaning, and covered in dust and blood, Red Kara struggled to get back to her feet. Perhaps hoping to catch Kara off guard, she lurched forward, almost drunkenly swinging one punch after another, but Kara just kept dodging, streaks of lightning dancing along her movements as she reappeared to her double's left, to her right, and behind her, her fists never leaving her hips. Something had triggered her mind to invoke Barry's speed, and now Red Kara was on her desperate last gasps.

Finally, perhaps out of pure frustration, Red Kara leapt into the air, attempting a knockout blow from above, but by this point Kara's newfound speed was unmatchable. She flew up, caught Red Kara in midair, and slammed her back into the ground, her hand on her double's throat. She pulled back her other fist to finally end her tormentor.

Coughing, spitting out blood, Red Kara refused to go quietly. "You'll never get rid of me," she taunted. "I'm a part of you."

Kneeling there, her weight holding her mirror image down as she prepared for the finishing blow, Kara gazed into her own face and was forced to appreciate for the first time how her own features looked when she was angry. Jealous. Afraid.

She hated it. She hated what these ugly feelings did to her. Fundamentally, though, beneath the blood and the bruises and the dirt, she found she couldn't ignore something else.

She _was_ still the same.

Not in the way Red Kara wanted her to believe, though. She wasn't the tyrannical, power-obsessed alien currently on the ground at her mercy, but it was a lie to say she never had the awful feelings her double proudly advertised, and in spite of Red Kara's vitriol, she still had the same eyes as Kara. The same body. The same heart.

Looking at this perverse but superficially identical version of herself, Kara had a moment of clarity. By themselves, these terrible feelings that sometimes floated through her mind didn't define her. They didn't _make_ her a monster. Her evil twin represented a choice, a possibility of which she'd forever have to remain cautious, but she was just that. A choice, not destiny. At the end of the day, Kara realized she didn't have to be afraid of how far she could fall. With her loved ones at her side, she'd always find her way as a force for good, whether her path took her forwards, backwards, down, or up, up, and away.

"You are a part of me," Kara admitted finally, letting go of her double, lowering her fist, and standing up. Shaking her head, the conviction absolute in her voice, she finished, "But you're not who I am."

At her words, Red Kara's form began to lighten and fade away, but Kara could still see her double's eyes narrow, whether out of hatred or grudging respect she couldn't tell, and at that point, it didn't matter. Within seconds, Kara was alone in her dream, and looking up, she saw that the National City of her mind had completely restored itself, all the damage and all the ruined buildings suddenly erased in favor of tranquility. Sighing, Kara let the corners of her mouth tilt up just slightly as she leaned her head back and closed her eyes.

…

She could feel the little smile still on her face even as her eyelids cracked open.

She was in a different medical lab from the one in which she'd woken to a panic attack, as this room had no hole in its roof. She felt herself covered in the medical gown and was relieved to be out of the aggressive, alternate Supergirl suit she'd been wearing. Alex had fallen asleep on one side of her, her sister's hand clasping Kara's while her other arm cushioned her head. On Kara's other side, Barry was asleep as well, the top of his head nestled against her hip. Her mind still in a bit of a fog, it was nevertheless now obvious to her why her mind specifically tapped into thoughts of them for support during her mental struggle.

Gently, she squeezed Alex's hand while putting her other hand on top of Barry's head, waking them both up. The way both their faces lit up upon seeing her awake was more healing than anything Kara could have asked for.

Alex hugged her first, gently, using both of her arms to pull Kara's head into her. "I am so glad you're okay," she whispered.

"Me too," Kara replied, pressing her face into Alex's shoulder. They had matching tears forming in their eyes when they pulled back to look at each other, but the joy in their faces was undeniable as well.

"Why do you do this to me?" Alex asked, not for the first time, smiling in exasperation.

"Because I'm your sister and you love me," Kara replied, repeating an exchange the two of them had had many times before and likely would have many more times in the future. Alex tilted her head to the side and chuckled, never having a good comeback to such a simple truth.

Barry was next. "I'm so sorry, Kara," he began, his voice muffled against her shoulder. "I'm so—"

Kara shook her head as she held Barry tightly against her with her arm. Smiling a little to herself, she joked, "You didn't kill me, so my day is looking up," recalling the same thing he said to her when Dominators had attacked the first time. Barry laughed, remembering as well. Pulling back slightly, she placed on a hand on his cheek. "It's not your fault."

She could tell by his eyes that Barry wasn't completely over this, and that they'd probably still have to talk about it in the days to come, but right now all they needed from one other was support. Barry leaned his face into her hand, the two of them reveling in each other's touch again. "I love you," he said.

"I love you, too," she said, smiling as they leaned into a kiss.

Hearing footsteps, everyone turned to see a bleary-eyed Caitlin walk into the lab, having spent a fitful night in her office. Her smile of relief, however, mirrored the ones on all of their faces as she saw Kara hugging her loved ones. "Well, that's a good sign," she commented.

"Is she going to be okay?" Barry asked, his arm around Kara's shoulders while Alex held her hand.

Going to a computer, Caitlin began scanning Kara's vital readings. "I think so," she replied, the relief clear in her voice. "Everything looks stable, but I would still advise taking it easy and resting since—"

Which is as far as she could get, as Kara was so excited to hear that her vitals were normal that she immediately sat up. Suddenly, a wave of nausea overcame her, and she promptly tilted over the side of the bed and vomited on the ground, right next to Barry's feet.

"…since the V-9 might still leave other side effects," Caitlin finished, looking down at the sick now splattering the floor.

Kara groaned, the dizziness not going away as Barry's hands slid up the sides of her head, carefully gathering her long hair away from her mouth.

"Gross," Alex pointed out unnecessarily, leaning over to rub Kara's back.

…

"Why aren't you resting at Barry's place?" Alex asked.

"Barry said Joe makes the best homemade chicken soup," Kara replied.

"He does," Barry confirmed.

"I do," Joe called out from the kitchen.

"You both have superspeed," Alex persisted. "You two each have your own homes in Central City _and_ National City. Why do you always end up here?"

The only response she received was laughter from everyone. "Don't bother, Alex," Joe called out, still bustling around the kitchen. "I've tried having this conversation with them already."

"Whatever," Alex said, surrendering the point. "I really should get going, though. Let you get your rest."

"I'm getting plenty of rest the way things are," Kara insisted.

"Okay, honestly, I've just had enough of third-wheeling the two of you," Alex shot back, looking meaningfully at her and Barry.

"I don't know what you're talking about," Kara replied, snuggling into Alex and readjusting her head on her sister's shoulder. "Barry's the third wheel here."

"It's true. I accepted that long ago," Barry quipped.

They were indeed back at Joe's house, on the couch watching television. Kara was spread out liberally, one might even argue luxuriously, on the couch, leaning against Alex at one end while her legs were firmly planted in Barry's lap at the other. She was still weak and nauseous after waking up that morning, and since she'd gotten confirmation that Sara had been able to free the rest of the League, she decided to listen to Caitlin's advice.

A small jump at both ends of the couch caused Alex and Barry to check their phones. "J'onn says the DEO's tracked down both Psi and Rainbow Raider. They're getting locked up," Alex reported.

"The League's sweeping around the world, tracking down Dominator transmitters and looking for anything like the ship you found," Barry added, reading off his phone. "It looks like that Dominator was a rogue agent, though. Working alone."

"Good," Kara said, "because let me tell you, Kryptonian biology and speedster drugs?" She exhaled dramatically. " _Really_ bad combination. Let's not do that again."

"No arguments here." The group lapsed into peaceful silence for a few minutes, not really watching the screen in front of them so much as just appreciating a crisis ending with everyone coming out okay.

Alex's phone began to ring. She checked it, then said, "Oh Kara, get up. I have to take this."

"No," Kara replied, pinning her sister's body underneath her.

"Seriously, Kara. Get off me!"

"No!"

"Kara, it's Maggie! I want to talk to her."

" _Fine_ ," Kara groaned, making an exaggerated show of moving her body so that her sister could stand up. "Go talk to your girlfriend. Leave me here," she pouted.

Alex shook her head. "You are so much work, you know that?"

"Hmmph," Kara grunted. As Alex headed into an adjoining room, Kara let go of her bit and turned her head, calling out, "Tell Maggie I said hi. And that I'm fine." Alex nodded to indicate she'd heard before walking out.

Deprived of her human pillow, Kara shifted around to lean into Barry instead, who opened his arms up automatically, his eyes never coming off the television. "By the way, Alex can say that to me, not you," she said, getting comfortable as his arms wrapped around her.

"What, that you're so much work, or that you need to get off?" he teased, as her head found a crook underneath his chin.

"Yes," she replied simply. She felt his lips smile into the top of her head.

They sat for a while, Barry's thumb making small circles on her shoulder, happy to be in each other's arms once again. "I know you've still got recovering to do," Barry began, "but whenever you feel like talking about what happened, I'm here. We all are."

Kara nodded slowly. She'd told the team briefly of the mental duel she'd had, but while she knew they had a sense of how significant the experience had been for her, she hadn't had the strength to go over everything in detail just yet. It wasn't like a switch had been flipped and she could suddenly, perfectly handle all of her demons. Far from it. Still, it had been a meaningful encounter, and anything that reaffirmed the support she had from the people she loved was an encounter worth appreciating.

"I know," Kara replied, smiling to herself. "That's what I'm counting on."

/end

…

 _Author's notes: A couple lines of direct dialogue are taken from Supergirl 1x01, "Pilot," and The Flash 3x08, "Invasion!"_

 _Thanks for giving this story a chance. I really do appreciate it._


End file.
